Try for backport

third_party/sqlite/amalgamation/sqlite3.05.c

+/************** Begin file trigger.c *****************************************/
+/*
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the implementation for TRIGGERs
+*/
+/* #include "sqliteInt.h" */
+
+#ifndef SQLITE_OMIT_TRIGGER
+/*
+** Delete a linked list of TriggerStep structures.
+*/
+SQLITE_PRIVATE void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){
+  while( pTriggerStep ){
+    TriggerStep * pTmp = pTriggerStep;
+    pTriggerStep = pTriggerStep->pNext;
+
+    sqlite3ExprDelete(db, pTmp->pWhere);
+    sqlite3ExprListDelete(db, pTmp->pExprList);
+    sqlite3SelectDelete(db, pTmp->pSelect);
+    sqlite3IdListDelete(db, pTmp->pIdList);
+
+    sqlite3DbFree(db, pTmp);
+  }
+}
+
+/*
+** Given table pTab, return a list of all the triggers attached to 
+** the table. The list is connected by Trigger.pNext pointers.
+**
+** All of the triggers on pTab that are in the same database as pTab
+** are already attached to pTab->pTrigger.  But there might be additional
+** triggers on pTab in the TEMP schema.  This routine prepends all
+** TEMP triggers on pTab to the beginning of the pTab->pTrigger list
+** and returns the combined list.
+**
+** To state it another way:  This routine returns a list of all triggers
+** that fire off of pTab.  The list will include any TEMP triggers on
+** pTab as well as the triggers lised in pTab->pTrigger.
+*/
+SQLITE_PRIVATE Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
+  Schema * const pTmpSchema = pParse->db->aDb[1].pSchema;
+  Trigger *pList = 0;                  /* List of triggers to return */
+
+  if( pParse->disableTriggers ){
+    return 0;
+  }
+
+  if( pTmpSchema!=pTab->pSchema ){
+    HashElem *p;
+    assert( sqlite3SchemaMutexHeld(pParse->db, 0, pTmpSchema) );
+    for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){
+      Trigger *pTrig = (Trigger *)sqliteHashData(p);
+      if( pTrig->pTabSchema==pTab->pSchema
+       && 0==sqlite3StrICmp(pTrig->table, pTab->zName) 
+      ){
+        pTrig->pNext = (pList ? pList : pTab->pTrigger);
+        pList = pTrig;
+      }
+    }
+  }
+
+  return (pList ? pList : pTab->pTrigger);
+}
+
+/*
+** This is called by the parser when it sees a CREATE TRIGGER statement
+** up to the point of the BEGIN before the trigger actions.  A Trigger
+** structure is generated based on the information available and stored
+** in pParse->pNewTrigger.  After the trigger actions have been parsed, the
+** sqlite3FinishTrigger() function is called to complete the trigger
+** construction process.
+*/
+SQLITE_PRIVATE void sqlite3BeginTrigger(
+  Parse *pParse,      /* The parse context of the CREATE TRIGGER statement */
+  Token *pName1,      /* The name of the trigger */
+  Token *pName2,      /* The name of the trigger */
+  int tr_tm,          /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
+  int op,             /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
+  IdList *pColumns,   /* column list if this is an UPDATE OF trigger */
+  SrcList *pTableName,/* The name of the table/view the trigger applies to */
+  Expr *pWhen,        /* WHEN clause */
+  int isTemp,         /* True if the TEMPORARY keyword is present */
+  int noErr           /* Suppress errors if the trigger already exists */
+){
+  Trigger *pTrigger = 0;  /* The new trigger */
+  Table *pTab;            /* Table that the trigger fires off of */
+  char *zName = 0;        /* Name of the trigger */
+  sqlite3 *db = pParse->db;  /* The database connection */
+  int iDb;                /* The database to store the trigger in */
+  Token *pName;           /* The unqualified db name */
+  DbFixer sFix;           /* State vector for the DB fixer */
+  int iTabDb;             /* Index of the database holding pTab */
+
+  assert( pName1!=0 );   /* pName1->z might be NULL, but not pName1 itself */
+  assert( pName2!=0 );
+  assert( op==TK_INSERT || op==TK_UPDATE || op==TK_DELETE );
+  assert( op>0 && op<0xff );
+  if( isTemp ){
+    /* If TEMP was specified, then the trigger name may not be qualified. */
+    if( pName2->n>0 ){
+      sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
+      goto trigger_cleanup;
+    }
+    iDb = 1;
+    pName = pName1;
+  }else{
+    /* Figure out the db that the trigger will be created in */
+    iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
+    if( iDb<0 ){
+      goto trigger_cleanup;
+    }
+  }
+  if( !pTableName || db->mallocFailed ){
+    goto trigger_cleanup;
+  }
+
+  /* A long-standing parser bug is that this syntax was allowed:
+  **
+  **    CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
+  **                                                 ^^^^^^^^
+  **
+  ** To maintain backwards compatibility, ignore the database
+  ** name on pTableName if we are reparsing out of SQLITE_MASTER.
+  */
+  if( db->init.busy && iDb!=1 ){
+    sqlite3DbFree(db, pTableName->a[0].zDatabase);
+    pTableName->a[0].zDatabase = 0;
+  }
+
+  /* If the trigger name was unqualified, and the table is a temp table,
+  ** then set iDb to 1 to create the trigger in the temporary database.
+  ** If sqlite3SrcListLookup() returns 0, indicating the table does not
+  ** exist, the error is caught by the block below.
+  */
+  pTab = sqlite3SrcListLookup(pParse, pTableName);
+  if( db->init.busy==0 && pName2->n==0 && pTab
+        && pTab->pSchema==db->aDb[1].pSchema ){
+    iDb = 1;
+  }
+
+  /* Ensure the table name matches database name and that the table exists */
+  if( db->mallocFailed ) goto trigger_cleanup;
+  assert( pTableName->nSrc==1 );
+  sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);
+  if( sqlite3FixSrcList(&sFix, pTableName) ){
+    goto trigger_cleanup;
+  }
+  pTab = sqlite3SrcListLookup(pParse, pTableName);
+  if( !pTab ){
+    /* The table does not exist. */
+    if( db->init.iDb==1 ){
+      /* Ticket #3810.
+      ** Normally, whenever a table is dropped, all associated triggers are
+      ** dropped too.  But if a TEMP trigger is created on a non-TEMP table
+      ** and the table is dropped by a different database connection, the
+      ** trigger is not visible to the database connection that does the
+      ** drop so the trigger cannot be dropped.  This results in an
+      ** "orphaned trigger" - a trigger whose associated table is missing.
+      */
+      db->init.orphanTrigger = 1;
+    }
+    goto trigger_cleanup;
+  }
+  if( IsVirtual(pTab) ){
+    sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
+    goto trigger_cleanup;
+  }
+
+  /* Check that the trigger name is not reserved and that no trigger of the
+  ** specified name exists */
+  zName = sqlite3NameFromToken(db, pName);
+  if( !zName || SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+    goto trigger_cleanup;
+  }
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
+    if( !noErr ){
+      sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
+    }else{
+      assert( !db->init.busy );
+      sqlite3CodeVerifySchema(pParse, iDb);
+    }
+    goto trigger_cleanup;
+  }
+
+  /* Do not create a trigger on a system table */
+  if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
+    sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
+    goto trigger_cleanup;
+  }
+
+  /* INSTEAD of triggers are only for views and views only support INSTEAD
+  ** of triggers.
+  */
+  if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
+    sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S", 
+        (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
+    goto trigger_cleanup;
+  }
+  if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
+    sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
+        " trigger on table: %S", pTableName, 0);
+    goto trigger_cleanup;
+  }
+  iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code = SQLITE_CREATE_TRIGGER;
+    const char *zDb = db->aDb[iTabDb].zName;
+    const char *zDbTrig = isTemp ? db->aDb[1].zName : zDb;
+    if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
+    if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
+      goto trigger_cleanup;
+    }
+    if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
+      goto trigger_cleanup;
+    }
+  }
+#endif
+
+  /* INSTEAD OF triggers can only appear on views and BEFORE triggers
+  ** cannot appear on views.  So we might as well translate every
+  ** INSTEAD OF trigger into a BEFORE trigger.  It simplifies code
+  ** elsewhere.
+  */
+  if (tr_tm == TK_INSTEAD){
+    tr_tm = TK_BEFORE;
+  }
+
+  /* Build the Trigger object */
+  pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
+  if( pTrigger==0 ) goto trigger_cleanup;
+  pTrigger->zName = zName;
+  zName = 0;
+  pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
+  pTrigger->pSchema = db->aDb[iDb].pSchema;
+  pTrigger->pTabSchema = pTab->pSchema;
+  pTrigger->op = (u8)op;
+  pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
+  pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
+  pTrigger->pColumns = sqlite3IdListDup(db, pColumns);
+  assert( pParse->pNewTrigger==0 );
+  pParse->pNewTrigger = pTrigger;
+
+trigger_cleanup:
+  sqlite3DbFree(db, zName);
+  sqlite3SrcListDelete(db, pTableName);
+  sqlite3IdListDelete(db, pColumns);
+  sqlite3ExprDelete(db, pWhen);
+  if( !pParse->pNewTrigger ){
+    sqlite3DeleteTrigger(db, pTrigger);
+  }else{
+    assert( pParse->pNewTrigger==pTrigger );
+  }
+}
+
+/*
+** This routine is called after all of the trigger actions have been parsed
+** in order to complete the process of building the trigger.
+*/
+SQLITE_PRIVATE void sqlite3FinishTrigger(
+  Parse *pParse,          /* Parser context */
+  TriggerStep *pStepList, /* The triggered program */
+  Token *pAll             /* Token that describes the complete CREATE TRIGGER */
+){
+  Trigger *pTrig = pParse->pNewTrigger;   /* Trigger being finished */
+  char *zName;                            /* Name of trigger */
+  sqlite3 *db = pParse->db;               /* The database */
+  DbFixer sFix;                           /* Fixer object */
+  int iDb;                                /* Database containing the trigger */
+  Token nameToken;                        /* Trigger name for error reporting */
+
+  pParse->pNewTrigger = 0;
+  if( NEVER(pParse->nErr) || !pTrig ) goto triggerfinish_cleanup;
+  zName = pTrig->zName;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
+  pTrig->step_list = pStepList;
+  while( pStepList ){
+    pStepList->pTrig = pTrig;
+    pStepList = pStepList->pNext;
+  }
+  nameToken.z = pTrig->zName;
+  nameToken.n = sqlite3Strlen30(nameToken.z);
+  sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
+  if( sqlite3FixTriggerStep(&sFix, pTrig->step_list) 
+   || sqlite3FixExpr(&sFix, pTrig->pWhen) 
+  ){
+    goto triggerfinish_cleanup;
+  }
+
+  /* if we are not initializing,
+  ** build the sqlite_master entry
+  */
+  if( !db->init.busy ){
+    Vdbe *v;
+    char *z;
+
+    /* Make an entry in the sqlite_master table */
+    v = sqlite3GetVdbe(pParse);
+    if( v==0 ) goto triggerfinish_cleanup;
+    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
+    sqlite3NestedParse(pParse,
+       "INSERT INTO %Q.%s VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
+       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), zName,
+       pTrig->table, z);
+    sqlite3DbFree(db, z);
+    sqlite3ChangeCookie(pParse, iDb);
+    sqlite3VdbeAddParseSchemaOp(v, iDb,
+        sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));
+  }
+
+  if( db->init.busy ){
+    Trigger *pLink = pTrig;
+    Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
+    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+    pTrig = sqlite3HashInsert(pHash, zName, pTrig);
+    if( pTrig ){
+      db->mallocFailed = 1;
+    }else if( pLink->pSchema==pLink->pTabSchema ){
+      Table *pTab;
+      pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);
+      assert( pTab!=0 );
+      pLink->pNext = pTab->pTrigger;
+      pTab->pTrigger = pLink;
+    }
+  }
+
+triggerfinish_cleanup:
+  sqlite3DeleteTrigger(db, pTrig);
+  assert( !pParse->pNewTrigger );
+  sqlite3DeleteTriggerStep(db, pStepList);
+}
+
+/*
+** Turn a SELECT statement (that the pSelect parameter points to) into
+** a trigger step.  Return a pointer to a TriggerStep structure.
+**
+** The parser calls this routine when it finds a SELECT statement in
+** body of a TRIGGER.  
+*/
+SQLITE_PRIVATE TriggerStep *sqlite3TriggerSelectStep(sqlite3 *db, Select *pSelect){
+  TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
+  if( pTriggerStep==0 ) {
+    sqlite3SelectDelete(db, pSelect);
+    return 0;
+  }
+  pTriggerStep->op = TK_SELECT;
+  pTriggerStep->pSelect = pSelect;
+  pTriggerStep->orconf = OE_Default;
+  return pTriggerStep;
+}
+
+/*
+** Allocate space to hold a new trigger step.  The allocated space
+** holds both the TriggerStep object and the TriggerStep.target.z string.
+**
+** If an OOM error occurs, NULL is returned and db->mallocFailed is set.
+*/
+static TriggerStep *triggerStepAllocate(
+  sqlite3 *db,                /* Database connection */
+  u8 op,                      /* Trigger opcode */
+  Token *pName                /* The target name */
+){
+  TriggerStep *pTriggerStep;
+
+  pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);
+  if( pTriggerStep ){
+    char *z = (char*)&pTriggerStep[1];
+    memcpy(z, pName->z, pName->n);
+    sqlite3Dequote(z);
+    pTriggerStep->zTarget = z;
+    pTriggerStep->op = op;
+  }
+  return pTriggerStep;
+}
+
+/*
+** Build a trigger step out of an INSERT statement.  Return a pointer
+** to the new trigger step.
+**
+** The parser calls this routine when it sees an INSERT inside the
+** body of a trigger.
+*/
+SQLITE_PRIVATE TriggerStep *sqlite3TriggerInsertStep(
+  sqlite3 *db,        /* The database connection */
+  Token *pTableName,  /* Name of the table into which we insert */
+  IdList *pColumn,    /* List of columns in pTableName to insert into */
+  Select *pSelect,    /* A SELECT statement that supplies values */
+  u8 orconf           /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
+){
+  TriggerStep *pTriggerStep;
+
+  assert(pSelect != 0 || db->mallocFailed);
+
+  pTriggerStep = triggerStepAllocate(db, TK_INSERT, pTableName);
+  if( pTriggerStep ){
+    pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
+    pTriggerStep->pIdList = pColumn;
+    pTriggerStep->orconf = orconf;
+  }else{
+    sqlite3IdListDelete(db, pColumn);
+  }
+  sqlite3SelectDelete(db, pSelect);
+
+  return pTriggerStep;
+}
+
+/*
+** Construct a trigger step that implements an UPDATE statement and return
+** a pointer to that trigger step.  The parser calls this routine when it
+** sees an UPDATE statement inside the body of a CREATE TRIGGER.
+*/
+SQLITE_PRIVATE TriggerStep *sqlite3TriggerUpdateStep(
+  sqlite3 *db,         /* The database connection */
+  Token *pTableName,   /* Name of the table to be updated */
+  ExprList *pEList,    /* The SET clause: list of column and new values */
+  Expr *pWhere,        /* The WHERE clause */
+  u8 orconf            /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */
+){
+  TriggerStep *pTriggerStep;
+
+  pTriggerStep = triggerStepAllocate(db, TK_UPDATE, pTableName);
+  if( pTriggerStep ){
+    pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE);
+    pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
+    pTriggerStep->orconf = orconf;
+  }
+  sqlite3ExprListDelete(db, pEList);
+  sqlite3ExprDelete(db, pWhere);
+  return pTriggerStep;
+}
+
+/*
+** Construct a trigger step that implements a DELETE statement and return
+** a pointer to that trigger step.  The parser calls this routine when it
+** sees a DELETE statement inside the body of a CREATE TRIGGER.
+*/
+SQLITE_PRIVATE TriggerStep *sqlite3TriggerDeleteStep(
+  sqlite3 *db,            /* Database connection */
+  Token *pTableName,      /* The table from which rows are deleted */
+  Expr *pWhere            /* The WHERE clause */
+){
+  TriggerStep *pTriggerStep;
+
+  pTriggerStep = triggerStepAllocate(db, TK_DELETE, pTableName);
+  if( pTriggerStep ){
+    pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
+    pTriggerStep->orconf = OE_Default;
+  }
+  sqlite3ExprDelete(db, pWhere);
+  return pTriggerStep;
+}
+
+/* 
+** Recursively delete a Trigger structure
+*/
+SQLITE_PRIVATE void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){
+  if( pTrigger==0 ) return;
+  sqlite3DeleteTriggerStep(db, pTrigger->step_list);
+  sqlite3DbFree(db, pTrigger->zName);
+  sqlite3DbFree(db, pTrigger->table);
+  sqlite3ExprDelete(db, pTrigger->pWhen);
+  sqlite3IdListDelete(db, pTrigger->pColumns);
+  sqlite3DbFree(db, pTrigger);
+}
+
+/*
+** This function is called to drop a trigger from the database schema. 
+**
+** This may be called directly from the parser and therefore identifies
+** the trigger by name.  The sqlite3DropTriggerPtr() routine does the
+** same job as this routine except it takes a pointer to the trigger
+** instead of the trigger name.
+**/
+SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){
+  Trigger *pTrigger = 0;
+  int i;
+  const char *zDb;
+  const char *zName;
+  sqlite3 *db = pParse->db;
+
+  if( db->mallocFailed ) goto drop_trigger_cleanup;
+  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
+    goto drop_trigger_cleanup;
+  }
+
+  assert( pName->nSrc==1 );
+  zDb = pName->a[0].zDatabase;
+  zName = pName->a[0].zName;
+  assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
+  for(i=OMIT_TEMPDB; i<db->nDb; i++){
+    int j = (i<2) ? i^1 : i;  /* Search TEMP before MAIN */
+    if( zDb && sqlite3StrICmp(db->aDb[j].zName, zDb) ) continue;
+    assert( sqlite3SchemaMutexHeld(db, j, 0) );
+    pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);
+    if( pTrigger ) break;
+  }
+  if( !pTrigger ){
+    if( !noErr ){
+      sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
+    }else{
+      sqlite3CodeVerifyNamedSchema(pParse, zDb);
+    }
+    pParse->checkSchema = 1;
+    goto drop_trigger_cleanup;
+  }
+  sqlite3DropTriggerPtr(pParse, pTrigger);
+
+drop_trigger_cleanup:
+  sqlite3SrcListDelete(db, pName);
+}
+
+/*
+** Return a pointer to the Table structure for the table that a trigger
+** is set on.
+*/
+static Table *tableOfTrigger(Trigger *pTrigger){
+  return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table);
+}
+
+
+/*
+** Drop a trigger given a pointer to that trigger. 
+*/
+SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
+  Table   *pTable;
+  Vdbe *v;
+  sqlite3 *db = pParse->db;
+  int iDb;
+
+  iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
+  assert( iDb>=0 && iDb<db->nDb );
+  pTable = tableOfTrigger(pTrigger);
+  assert( pTable );
+  assert( pTable->pSchema==pTrigger->pSchema || iDb==1 );
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  {
+    int code = SQLITE_DROP_TRIGGER;
+    const char *zDb = db->aDb[iDb].zName;
+    const char *zTab = SCHEMA_TABLE(iDb);
+    if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
+    if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
+      sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
+      return;
+    }
+  }
+#endif
+
+  /* Generate code to destroy the database record of the trigger.
+  */
+  assert( pTable!=0 );
+  if( (v = sqlite3GetVdbe(pParse))!=0 ){
+    sqlite3NestedParse(pParse,
+       "DELETE FROM %Q.%s WHERE name=%Q AND type='trigger'",
+       db->aDb[iDb].zName, SCHEMA_TABLE(iDb), pTrigger->zName
+    );
+    sqlite3ChangeCookie(pParse, iDb);
+    sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
+  }
+}
+
+/*
+** Remove a trigger from the hash tables of the sqlite* pointer.
+*/
+SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
+  Trigger *pTrigger;
+  Hash *pHash;
+
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  pHash = &(db->aDb[iDb].pSchema->trigHash);
+  pTrigger = sqlite3HashInsert(pHash, zName, 0);
+  if( ALWAYS(pTrigger) ){
+    if( pTrigger->pSchema==pTrigger->pTabSchema ){
+      Table *pTab = tableOfTrigger(pTrigger);
+      Trigger **pp;
+      for(pp=&pTab->pTrigger; *pp!=pTrigger; pp=&((*pp)->pNext));
+      *pp = (*pp)->pNext;
+    }
+    sqlite3DeleteTrigger(db, pTrigger);
+    db->flags |= SQLITE_InternChanges;
+  }
+}
+
+/*
+** pEList is the SET clause of an UPDATE statement.  Each entry
+** in pEList is of the format <id>=<expr>.  If any of the entries
+** in pEList have an <id> which matches an identifier in pIdList,
+** then return TRUE.  If pIdList==NULL, then it is considered a
+** wildcard that matches anything.  Likewise if pEList==NULL then
+** it matches anything so always return true.  Return false only
+** if there is no match.
+*/
+static int checkColumnOverlap(IdList *pIdList, ExprList *pEList){
+  int e;
+  if( pIdList==0 || NEVER(pEList==0) ) return 1;
+  for(e=0; e<pEList->nExpr; e++){
+    if( sqlite3IdListIndex(pIdList, pEList->a[e].zName)>=0 ) return 1;
+  }
+  return 0; 
+}
+
+/*
+** Return a list of all triggers on table pTab if there exists at least
+** one trigger that must be fired when an operation of type 'op' is 
+** performed on the table, and, if that operation is an UPDATE, if at
+** least one of the columns in pChanges is being modified.
+*/
+SQLITE_PRIVATE Trigger *sqlite3TriggersExist(
+  Parse *pParse,          /* Parse context */
+  Table *pTab,            /* The table the contains the triggers */
+  int op,                 /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
+  ExprList *pChanges,     /* Columns that change in an UPDATE statement */
+  int *pMask              /* OUT: Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
+){
+  int mask = 0;
+  Trigger *pList = 0;
+  Trigger *p;
+
+  if( (pParse->db->flags & SQLITE_EnableTrigger)!=0 ){
+    pList = sqlite3TriggerList(pParse, pTab);
+  }
+  assert( pList==0 || IsVirtual(pTab)==0 );
+  for(p=pList; p; p=p->pNext){
+    if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){
+      mask |= p->tr_tm;
+    }
+  }
+  if( pMask ){
+    *pMask = mask;
+  }
+  return (mask ? pList : 0);
+}
+
+/*
+** Convert the pStep->zTarget string into a SrcList and return a pointer
+** to that SrcList.
+**
+** This routine adds a specific database name, if needed, to the target when
+** forming the SrcList.  This prevents a trigger in one database from
+** referring to a target in another database.  An exception is when the
+** trigger is in TEMP in which case it can refer to any other database it
+** wants.
+*/
+static SrcList *targetSrcList(
+  Parse *pParse,       /* The parsing context */
+  TriggerStep *pStep   /* The trigger containing the target token */
+){
+  sqlite3 *db = pParse->db;
+  int iDb;             /* Index of the database to use */
+  SrcList *pSrc;       /* SrcList to be returned */
+
+  pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
+  if( pSrc ){
+    assert( pSrc->nSrc>0 );
+    pSrc->a[pSrc->nSrc-1].zName = sqlite3DbStrDup(db, pStep->zTarget);
+    iDb = sqlite3SchemaToIndex(db, pStep->pTrig->pSchema);
+    if( iDb==0 || iDb>=2 ){
+      assert( iDb<db->nDb );
+      pSrc->a[pSrc->nSrc-1].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zName);
+    }
+  }
+  return pSrc;
+}
+
+/*
+** Generate VDBE code for the statements inside the body of a single 
+** trigger.
+*/
+static int codeTriggerProgram(
+  Parse *pParse,            /* The parser context */
+  TriggerStep *pStepList,   /* List of statements inside the trigger body */
+  int orconf                /* Conflict algorithm. (OE_Abort, etc) */  
+){
+  TriggerStep *pStep;
+  Vdbe *v = pParse->pVdbe;
+  sqlite3 *db = pParse->db;
+
+  assert( pParse->pTriggerTab && pParse->pToplevel );
+  assert( pStepList );
+  assert( v!=0 );
+  for(pStep=pStepList; pStep; pStep=pStep->pNext){
+    /* Figure out the ON CONFLICT policy that will be used for this step
+    ** of the trigger program. If the statement that caused this trigger
+    ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
+    ** the ON CONFLICT policy that was specified as part of the trigger
+    ** step statement. Example:
+    **
+    **   CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
+    **     INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
+    **   END;
+    **
+    **   INSERT INTO t1 ... ;            -- insert into t2 uses REPLACE policy
+    **   INSERT OR IGNORE INTO t1 ... ;  -- insert into t2 uses IGNORE policy
+    */
+    pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
+    assert( pParse->okConstFactor==0 );
+
+    switch( pStep->op ){
+      case TK_UPDATE: {
+        sqlite3Update(pParse, 
+          targetSrcList(pParse, pStep),
+          sqlite3ExprListDup(db, pStep->pExprList, 0), 
+          sqlite3ExprDup(db, pStep->pWhere, 0), 
+          pParse->eOrconf
+        );
+        break;
+      }
+      case TK_INSERT: {
+        sqlite3Insert(pParse, 
+          targetSrcList(pParse, pStep),
+          sqlite3SelectDup(db, pStep->pSelect, 0), 
+          sqlite3IdListDup(db, pStep->pIdList), 
+          pParse->eOrconf
+        );
+        break;
+      }
+      case TK_DELETE: {
+        sqlite3DeleteFrom(pParse, 
+          targetSrcList(pParse, pStep),
+          sqlite3ExprDup(db, pStep->pWhere, 0)
+        );
+        break;
+      }
+      default: assert( pStep->op==TK_SELECT ); {
+        SelectDest sDest;
+        Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
+        sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
+        sqlite3Select(pParse, pSelect, &sDest);
+        sqlite3SelectDelete(db, pSelect);
+        break;
+      }
+    } 
+    if( pStep->op!=TK_SELECT ){
+      sqlite3VdbeAddOp0(v, OP_ResetCount);
+    }
+  }
+
+  return 0;
+}
+
+#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
+/*
+** This function is used to add VdbeComment() annotations to a VDBE
+** program. It is not used in production code, only for debugging.
+*/
+static const char *onErrorText(int onError){
+  switch( onError ){
+    case OE_Abort:    return "abort";
+    case OE_Rollback: return "rollback";
+    case OE_Fail:     return "fail";
+    case OE_Replace:  return "replace";
+    case OE_Ignore:   return "ignore";
+    case OE_Default:  return "default";
+  }
+  return "n/a";
+}
+#endif
+
+/*
+** Parse context structure pFrom has just been used to create a sub-vdbe
+** (trigger program). If an error has occurred, transfer error information
+** from pFrom to pTo.
+*/
+static void transferParseError(Parse *pTo, Parse *pFrom){
+  assert( pFrom->zErrMsg==0 || pFrom->nErr );
+  assert( pTo->zErrMsg==0 || pTo->nErr );
+  if( pTo->nErr==0 ){
+    pTo->zErrMsg = pFrom->zErrMsg;
+    pTo->nErr = pFrom->nErr;
+    pTo->rc = pFrom->rc;
+  }else{
+    sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
+  }
+}
+
+/*
+** Create and populate a new TriggerPrg object with a sub-program 
+** implementing trigger pTrigger with ON CONFLICT policy orconf.
+*/
+static TriggerPrg *codeRowTrigger(
+  Parse *pParse,       /* Current parse context */
+  Trigger *pTrigger,   /* Trigger to code */
+  Table *pTab,         /* The table pTrigger is attached to */
+  int orconf           /* ON CONFLICT policy to code trigger program with */
+){
+  Parse *pTop = sqlite3ParseToplevel(pParse);
+  sqlite3 *db = pParse->db;   /* Database handle */
+  TriggerPrg *pPrg;           /* Value to return */
+  Expr *pWhen = 0;            /* Duplicate of trigger WHEN expression */
+  Vdbe *v;                    /* Temporary VM */
+  NameContext sNC;            /* Name context for sub-vdbe */
+  SubProgram *pProgram = 0;   /* Sub-vdbe for trigger program */
+  Parse *pSubParse;           /* Parse context for sub-vdbe */
+  int iEndTrigger = 0;        /* Label to jump to if WHEN is false */
+
+  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
+  assert( pTop->pVdbe );
+
+  /* Allocate the TriggerPrg and SubProgram objects. To ensure that they
+  ** are freed if an error occurs, link them into the Parse.pTriggerPrg 
+  ** list of the top-level Parse object sooner rather than later.  */
+  pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));
+  if( !pPrg ) return 0;
+  pPrg->pNext = pTop->pTriggerPrg;
+  pTop->pTriggerPrg = pPrg;
+  pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));
+  if( !pProgram ) return 0;
+  sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram);
+  pPrg->pTrigger = pTrigger;
+  pPrg->orconf = orconf;
+  pPrg->aColmask[0] = 0xffffffff;
+  pPrg->aColmask[1] = 0xffffffff;
+
+  /* Allocate and populate a new Parse context to use for coding the 
+  ** trigger sub-program.  */
+  pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));
+  if( !pSubParse ) return 0;
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pSubParse;
+  pSubParse->db = db;
+  pSubParse->pTriggerTab = pTab;
+  pSubParse->pToplevel = pTop;
+  pSubParse->zAuthContext = pTrigger->zName;
+  pSubParse->eTriggerOp = pTrigger->op;
+  pSubParse->nQueryLoop = pParse->nQueryLoop;
+
+  v = sqlite3GetVdbe(pSubParse);
+  if( v ){
+    VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", 
+      pTrigger->zName, onErrorText(orconf),
+      (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),
+        (pTrigger->op==TK_UPDATE ? "UPDATE" : ""),
+        (pTrigger->op==TK_INSERT ? "INSERT" : ""),
+        (pTrigger->op==TK_DELETE ? "DELETE" : ""),
+      pTab->zName
+    ));
+#ifndef SQLITE_OMIT_TRACE
+    sqlite3VdbeChangeP4(v, -1, 
+      sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC
+    );
+#endif
+
+    /* If one was specified, code the WHEN clause. If it evaluates to false
+    ** (or NULL) the sub-vdbe is immediately halted by jumping to the 
+    ** OP_Halt inserted at the end of the program.  */
+    if( pTrigger->pWhen ){
+      pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);
+      if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) 
+       && db->mallocFailed==0 
+      ){
+        iEndTrigger = sqlite3VdbeMakeLabel(v);
+        sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);
+      }
+      sqlite3ExprDelete(db, pWhen);
+    }
+
+    /* Code the trigger program into the sub-vdbe. */
+    codeTriggerProgram(pSubParse, pTrigger->step_list, orconf);
+
+    /* Insert an OP_Halt at the end of the sub-program. */
+    if( iEndTrigger ){
+      sqlite3VdbeResolveLabel(v, iEndTrigger);
+    }
+    sqlite3VdbeAddOp0(v, OP_Halt);
+    VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));
+
+    transferParseError(pParse, pSubParse);
+    if( db->mallocFailed==0 ){
+      pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);
+    }
+    pProgram->nMem = pSubParse->nMem;
+    pProgram->nCsr = pSubParse->nTab;
+    pProgram->nOnce = pSubParse->nOnce;
+    pProgram->token = (void *)pTrigger;
+    pPrg->aColmask[0] = pSubParse->oldmask;
+    pPrg->aColmask[1] = pSubParse->newmask;
+    sqlite3VdbeDelete(v);
+  }
+
+  assert( !pSubParse->pAinc       && !pSubParse->pZombieTab );
+  assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );
+  sqlite3ParserReset(pSubParse);
+  sqlite3StackFree(db, pSubParse);
+
+  return pPrg;
+}
+    
+/*
+** Return a pointer to a TriggerPrg object containing the sub-program for
+** trigger pTrigger with default ON CONFLICT algorithm orconf. If no such
+** TriggerPrg object exists, a new object is allocated and populated before
+** being returned.
+*/
+static TriggerPrg *getRowTrigger(
+  Parse *pParse,       /* Current parse context */
+  Trigger *pTrigger,   /* Trigger to code */
+  Table *pTab,         /* The table trigger pTrigger is attached to */
+  int orconf           /* ON CONFLICT algorithm. */
+){
+  Parse *pRoot = sqlite3ParseToplevel(pParse);
+  TriggerPrg *pPrg;
+
+  assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
+
+  /* It may be that this trigger has already been coded (or is in the
+  ** process of being coded). If this is the case, then an entry with
+  ** a matching TriggerPrg.pTrigger field will be present somewhere
+  ** in the Parse.pTriggerPrg list. Search for such an entry.  */
+  for(pPrg=pRoot->pTriggerPrg; 
+      pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf); 
+      pPrg=pPrg->pNext
+  );
+
+  /* If an existing TriggerPrg could not be located, create a new one. */
+  if( !pPrg ){
+    pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf);
+  }
+
+  return pPrg;
+}
+
+/*
+** Generate code for the trigger program associated with trigger p on 
+** table pTab. The reg, orconf and ignoreJump parameters passed to this
+** function are the same as those described in the header function for
+** sqlite3CodeRowTrigger()
+*/
+SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(
+  Parse *pParse,       /* Parse context */
+  Trigger *p,          /* Trigger to code */
+  Table *pTab,         /* The table to code triggers from */
+  int reg,             /* Reg array containing OLD.* and NEW.* values */
+  int orconf,          /* ON CONFLICT policy */
+  int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */
+){
+  Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */
+  TriggerPrg *pPrg;
+  pPrg = getRowTrigger(pParse, p, pTab, orconf);
+  assert( pPrg || pParse->nErr || pParse->db->mallocFailed );
+
+  /* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program 
+  ** is a pointer to the sub-vdbe containing the trigger program.  */
+  if( pPrg ){
+    int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));
+
+    sqlite3VdbeAddOp3(v, OP_Program, reg, ignoreJump, ++pParse->nMem);
+    sqlite3VdbeChangeP4(v, -1, (const char *)pPrg->pProgram, P4_SUBPROGRAM);
+    VdbeComment(
+        (v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));
+
+    /* Set the P5 operand of the OP_Program instruction to non-zero if
+    ** recursive invocation of this trigger program is disallowed. Recursive
+    ** invocation is disallowed if (a) the sub-program is really a trigger,
+    ** not a foreign key action, and (b) the flag to enable recursive triggers
+    ** is clear.  */
+    sqlite3VdbeChangeP5(v, (u8)bRecursive);
+  }
+}
+
+/*
+** This is called to code the required FOR EACH ROW triggers for an operation
+** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
+** is given by the op parameter. The tr_tm parameter determines whether the
+** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
+** parameter pChanges is passed the list of columns being modified.
+**
+** If there are no triggers that fire at the specified time for the specified
+** operation on pTab, this function is a no-op.
+**
+** The reg argument is the address of the first in an array of registers 
+** that contain the values substituted for the new.* and old.* references
+** in the trigger program. If N is the number of columns in table pTab
+** (a copy of pTab->nCol), then registers are populated as follows:
+**
+**   Register       Contains
+**   ------------------------------------------------------
+**   reg+0          OLD.rowid
+**   reg+1          OLD.* value of left-most column of pTab
+**   ...            ...
+**   reg+N          OLD.* value of right-most column of pTab
+**   reg+N+1        NEW.rowid
+**   reg+N+2        OLD.* value of left-most column of pTab
+**   ...            ...
+**   reg+N+N+1      NEW.* value of right-most column of pTab
+**
+** For ON DELETE triggers, the registers containing the NEW.* values will
+** never be accessed by the trigger program, so they are not allocated or 
+** populated by the caller (there is no data to populate them with anyway). 
+** Similarly, for ON INSERT triggers the values stored in the OLD.* registers
+** are never accessed, and so are not allocated by the caller. So, for an
+** ON INSERT trigger, the value passed to this function as parameter reg
+** is not a readable register, although registers (reg+N) through 
+** (reg+N+N+1) are.
+**
+** Parameter orconf is the default conflict resolution algorithm for the
+** trigger program to use (REPLACE, IGNORE etc.). Parameter ignoreJump
+** is the instruction that control should jump to if a trigger program
+** raises an IGNORE exception.
+*/
+SQLITE_PRIVATE void sqlite3CodeRowTrigger(
+  Parse *pParse,       /* Parse context */
+  Trigger *pTrigger,   /* List of triggers on table pTab */
+  int op,              /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
+  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */
+  int tr_tm,           /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
+  Table *pTab,         /* The table to code triggers from */
+  int reg,             /* The first in an array of registers (see above) */
+  int orconf,          /* ON CONFLICT policy */
+  int ignoreJump       /* Instruction to jump to for RAISE(IGNORE) */
+){
+  Trigger *p;          /* Used to iterate through pTrigger list */
+
+  assert( op==TK_UPDATE || op==TK_INSERT || op==TK_DELETE );
+  assert( tr_tm==TRIGGER_BEFORE || tr_tm==TRIGGER_AFTER );
+  assert( (op==TK_UPDATE)==(pChanges!=0) );
+
+  for(p=pTrigger; p; p=p->pNext){
+
+    /* Sanity checking:  The schema for the trigger and for the table are
+    ** always defined.  The trigger must be in the same schema as the table
+    ** or else it must be a TEMP trigger. */
+    assert( p->pSchema!=0 );
+    assert( p->pTabSchema!=0 );
+    assert( p->pSchema==p->pTabSchema 
+         || p->pSchema==pParse->db->aDb[1].pSchema );
+
+    /* Determine whether we should code this trigger */
+    if( p->op==op 
+     && p->tr_tm==tr_tm 
+     && checkColumnOverlap(p->pColumns, pChanges)
+    ){
+      sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump);
+    }
+  }
+}
+
+/*
+** Triggers may access values stored in the old.* or new.* pseudo-table. 
+** This function returns a 32-bit bitmask indicating which columns of the 
+** old.* or new.* tables actually are used by triggers. This information 
+** may be used by the caller, for example, to avoid having to load the entire
+** old.* record into memory when executing an UPDATE or DELETE command.
+**
+** Bit 0 of the returned mask is set if the left-most column of the
+** table may be accessed using an [old|new].<col> reference. Bit 1 is set if
+** the second leftmost column value is required, and so on. If there
+** are more than 32 columns in the table, and at least one of the columns
+** with an index greater than 32 may be accessed, 0xffffffff is returned.
+**
+** It is not possible to determine if the old.rowid or new.rowid column is 
+** accessed by triggers. The caller must always assume that it is.
+**
+** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned
+** applies to the old.* table. If 1, the new.* table.
+**
+** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE
+** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only
+** included in the returned mask if the TRIGGER_BEFORE bit is set in the
+** tr_tm parameter. Similarly, values accessed by AFTER triggers are only
+** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm.
+*/
+SQLITE_PRIVATE u32 sqlite3TriggerColmask(
+  Parse *pParse,       /* Parse context */
+  Trigger *pTrigger,   /* List of triggers on table pTab */
+  ExprList *pChanges,  /* Changes list for any UPDATE OF triggers */
+  int isNew,           /* 1 for new.* ref mask, 0 for old.* ref mask */
+  int tr_tm,           /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
+  Table *pTab,         /* The table to code triggers from */
+  int orconf           /* Default ON CONFLICT policy for trigger steps */
+){
+  const int op = pChanges ? TK_UPDATE : TK_DELETE;
+  u32 mask = 0;
+  Trigger *p;
+
+  assert( isNew==1 || isNew==0 );
+  for(p=pTrigger; p; p=p->pNext){
+    if( p->op==op && (tr_tm&p->tr_tm)
+     && checkColumnOverlap(p->pColumns,pChanges)
+    ){
+      TriggerPrg *pPrg;
+      pPrg = getRowTrigger(pParse, p, pTab, orconf);
+      if( pPrg ){
+        mask |= pPrg->aColmask[isNew];
+      }
+    }
+  }
+
+  return mask;
+}
+
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
+
+/************** End of trigger.c *********************************************/
+/************** Begin file update.c ******************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that are called by the parser
+** to handle UPDATE statements.
+*/
+/* #include "sqliteInt.h" */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Forward declaration */
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowidExpr,    /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
+  int onError          /* ON CONFLICT strategy */
+);
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** The most recently coded instruction was an OP_Column to retrieve the
+** i-th column of table pTab. This routine sets the P4 parameter of the 
+** OP_Column to the default value, if any.
+**
+** The default value of a column is specified by a DEFAULT clause in the 
+** column definition. This was either supplied by the user when the table
+** was created, or added later to the table definition by an ALTER TABLE
+** command. If the latter, then the row-records in the table btree on disk
+** may not contain a value for the column and the default value, taken
+** from the P4 parameter of the OP_Column instruction, is returned instead.
+** If the former, then all row-records are guaranteed to include a value
+** for the column and the P4 value is not required.
+**
+** Column definitions created by an ALTER TABLE command may only have 
+** literal default values specified: a number, null or a string. (If a more
+** complicated default expression value was provided, it is evaluated 
+** when the ALTER TABLE is executed and one of the literal values written
+** into the sqlite_master table.)
+**
+** Therefore, the P4 parameter is only required if the default value for
+** the column is a literal number, string or null. The sqlite3ValueFromExpr()
+** function is capable of transforming these types of expressions into
+** sqlite3_value objects.
+**
+** If parameter iReg is not negative, code an OP_RealAffinity instruction
+** on register iReg. This is used when an equivalent integer value is 
+** stored in place of an 8-byte floating point value in order to save 
+** space.
+*/
+SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
+  assert( pTab!=0 );
+  if( !pTab->pSelect ){
+    sqlite3_value *pValue = 0;
+    u8 enc = ENC(sqlite3VdbeDb(v));
+    Column *pCol = &pTab->aCol[i];
+    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
+    assert( i<pTab->nCol );
+    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
+                         pCol->affinity, &pValue);
+    if( pValue ){
+      sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
+    }
+#ifndef SQLITE_OMIT_FLOATING_POINT
+    if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
+      sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
+    }
+#endif
+  }
+}
+
+/*
+** Process an UPDATE statement.
+**
+**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
+**          \_______/ \________/     \______/       \________________/
+*            onError   pTabList      pChanges             pWhere
+*/
+SQLITE_PRIVATE void sqlite3Update(
+  Parse *pParse,         /* The parser context */
+  SrcList *pTabList,     /* The table in which we should change things */
+  ExprList *pChanges,    /* Things to be changed */
+  Expr *pWhere,          /* The WHERE clause.  May be null */
+  int onError            /* How to handle constraint errors */
+){
+  int i, j;              /* Loop counters */
+  Table *pTab;           /* The table to be updated */
+  int addrTop = 0;       /* VDBE instruction address of the start of the loop */
+  WhereInfo *pWInfo;     /* Information about the WHERE clause */
+  Vdbe *v;               /* The virtual database engine */
+  Index *pIdx;           /* For looping over indices */
+  Index *pPk;            /* The PRIMARY KEY index for WITHOUT ROWID tables */
+  int nIdx;              /* Number of indices that need updating */
+  int iBaseCur;          /* Base cursor number */
+  int iDataCur;          /* Cursor for the canonical data btree */
+  int iIdxCur;           /* Cursor for the first index */
+  sqlite3 *db;           /* The database structure */
+  int *aRegIdx = 0;      /* One register assigned to each index to be updated */
+  int *aXRef = 0;        /* aXRef[i] is the index in pChanges->a[] of the
+                         ** an expression for the i-th column of the table.
+                         ** aXRef[i]==-1 if the i-th column is not changed. */
+  u8 *aToOpen;           /* 1 for tables and indices to be opened */
+  u8 chngPk;             /* PRIMARY KEY changed in a WITHOUT ROWID table */
+  u8 chngRowid;          /* Rowid changed in a normal table */
+  u8 chngKey;            /* Either chngPk or chngRowid */
+  Expr *pRowidExpr = 0;  /* Expression defining the new record number */
+  AuthContext sContext;  /* The authorization context */
+  NameContext sNC;       /* The name-context to resolve expressions in */
+  int iDb;               /* Database containing the table being updated */
+  int okOnePass;         /* True for one-pass algorithm without the FIFO */
+  int hasFK;             /* True if foreign key processing is required */
+  int labelBreak;        /* Jump here to break out of UPDATE loop */
+  int labelContinue;     /* Jump here to continue next step of UPDATE loop */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  int isView;            /* True when updating a view (INSTEAD OF trigger) */
+  Trigger *pTrigger;     /* List of triggers on pTab, if required */
+  int tmask;             /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
+#endif
+  int newmask;           /* Mask of NEW.* columns accessed by BEFORE triggers */
+  int iEph = 0;          /* Ephemeral table holding all primary key values */
+  int nKey = 0;          /* Number of elements in regKey for WITHOUT ROWID */
+  int aiCurOnePass[2];   /* The write cursors opened by WHERE_ONEPASS */
+
+  /* Register Allocations */
+  int regRowCount = 0;   /* A count of rows changed */
+  int regOldRowid = 0;   /* The old rowid */
+  int regNewRowid = 0;   /* The new rowid */
+  int regNew = 0;        /* Content of the NEW.* table in triggers */
+  int regOld = 0;        /* Content of OLD.* table in triggers */
+  int regRowSet = 0;     /* Rowset of rows to be updated */
+  int regKey = 0;        /* composite PRIMARY KEY value */
+
+  memset(&sContext, 0, sizeof(sContext));
+  db = pParse->db;
+  if( pParse->nErr || db->mallocFailed ){
+    goto update_cleanup;
+  }
+  assert( pTabList->nSrc==1 );
+
+  /* Locate the table which we want to update. 
+  */
+  pTab = sqlite3SrcListLookup(pParse, pTabList);
+  if( pTab==0 ) goto update_cleanup;
+  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+
+  /* Figure out if we have any triggers and if the table being
+  ** updated is a view.
+  */
+#ifndef SQLITE_OMIT_TRIGGER
+  pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
+  isView = pTab->pSelect!=0;
+  assert( pTrigger || tmask==0 );
+#else
+# define pTrigger 0
+# define isView 0
+# define tmask 0
+#endif
+#ifdef SQLITE_OMIT_VIEW
+# undef isView
+# define isView 0
+#endif
+
+  if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+    goto update_cleanup;
+  }
+  if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
+    goto update_cleanup;
+  }
+
+  /* Allocate a cursors for the main database table and for all indices.
+  ** The index cursors might not be used, but if they are used they
+  ** need to occur right after the database cursor.  So go ahead and
+  ** allocate enough space, just in case.
+  */
+  pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++;
+  iIdxCur = iDataCur+1;
+  pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
+  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
+    if( IsPrimaryKeyIndex(pIdx) && pPk!=0 ){
+      iDataCur = pParse->nTab;
+      pTabList->a[0].iCursor = iDataCur;
+    }
+    pParse->nTab++;
+  }
+
+  /* Allocate space for aXRef[], aRegIdx[], and aToOpen[].  
+  ** Initialize aXRef[] and aToOpen[] to their default values.
+  */
+  aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 );
+  if( aXRef==0 ) goto update_cleanup;
+  aRegIdx = aXRef+pTab->nCol;
+  aToOpen = (u8*)(aRegIdx+nIdx);
+  memset(aToOpen, 1, nIdx+1);
+  aToOpen[nIdx+1] = 0;
+  for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
+
+  /* Initialize the name-context */
+  memset(&sNC, 0, sizeof(sNC));
+  sNC.pParse = pParse;
+  sNC.pSrcList = pTabList;
+
+  /* Resolve the column names in all the expressions of the
+  ** of the UPDATE statement.  Also find the column index
+  ** for each column to be updated in the pChanges array.  For each
+  ** column to be updated, make sure we have authorization to change
+  ** that column.
+  */
+  chngRowid = chngPk = 0;
+  for(i=0; i<pChanges->nExpr; i++){
+    if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
+      goto update_cleanup;
+    }
+    for(j=0; j<pTab->nCol; j++){
+      if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
+        if( j==pTab->iPKey ){
+          chngRowid = 1;
+          pRowidExpr = pChanges->a[i].pExpr;
+        }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
+          chngPk = 1;
+        }
+        aXRef[j] = i;
+        break;
+      }
+    }
+    if( j>=pTab->nCol ){
+      if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
+        j = -1;
+        chngRowid = 1;
+        pRowidExpr = pChanges->a[i].pExpr;
+      }else{
+        sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
+        pParse->checkSchema = 1;
+        goto update_cleanup;
+      }
+    }
+#ifndef SQLITE_OMIT_AUTHORIZATION
+    {
+      int rc;
+      rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
+                            j<0 ? "ROWID" : pTab->aCol[j].zName,
+                            db->aDb[iDb].zName);
+      if( rc==SQLITE_DENY ){
+        goto update_cleanup;
+      }else if( rc==SQLITE_IGNORE ){
+        aXRef[j] = -1;
+      }
+    }
+#endif
+  }
+  assert( (chngRowid & chngPk)==0 );
+  assert( chngRowid==0 || chngRowid==1 );
+  assert( chngPk==0 || chngPk==1 );
+  chngKey = chngRowid + chngPk;
+
+  /* The SET expressions are not actually used inside the WHERE loop.  
+  ** So reset the colUsed mask. Unless this is a virtual table. In that
+  ** case, set all bits of the colUsed mask (to ensure that the virtual
+  ** table implementation makes all columns available).
+  */
+  pTabList->a[0].colUsed = IsVirtual(pTab) ? (Bitmask)-1 : 0;
+
+  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
+
+  /* There is one entry in the aRegIdx[] array for each index on the table
+  ** being updated.  Fill in aRegIdx[] with a register number that will hold
+  ** the key for accessing each index.
+  **
+  ** FIXME:  Be smarter about omitting indexes that use expressions.
+  */
+  for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+    int reg;
+    if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){
+      reg = ++pParse->nMem;
+    }else{
+      reg = 0;
+      for(i=0; i<pIdx->nKeyCol; i++){
+        i16 iIdxCol = pIdx->aiColumn[i];
+        if( iIdxCol<0 || aXRef[iIdxCol]>=0 ){
+          reg = ++pParse->nMem;
+          break;
+        }
+      }
+    }
+    if( reg==0 ) aToOpen[j+1] = 0;
+    aRegIdx[j] = reg;
+  }
+
+  /* Begin generating code. */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto update_cleanup;
+  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
+  sqlite3BeginWriteOperation(pParse, 1, iDb);
+
+  /* Allocate required registers. */
+  if( !IsVirtual(pTab) ){
+    regRowSet = ++pParse->nMem;
+    regOldRowid = regNewRowid = ++pParse->nMem;
+    if( chngPk || pTrigger || hasFK ){
+      regOld = pParse->nMem + 1;
+      pParse->nMem += pTab->nCol;
+    }
+    if( chngKey || pTrigger || hasFK ){
+      regNewRowid = ++pParse->nMem;
+    }
+    regNew = pParse->nMem + 1;
+    pParse->nMem += pTab->nCol;
+  }
+
+  /* Start the view context. */
+  if( isView ){
+    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
+  }
+
+  /* If we are trying to update a view, realize that view into
+  ** an ephemeral table.
+  */
+#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
+  if( isView ){
+    sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur);
+  }
+#endif
+
+  /* Resolve the column names in all the expressions in the
+  ** WHERE clause.
+  */
+  if( sqlite3ResolveExprNames(&sNC, pWhere) ){
+    goto update_cleanup;
+  }
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Virtual tables must be handled separately */
+  if( IsVirtual(pTab) ){
+    updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
+                       pWhere, onError);
+    goto update_cleanup;
+  }
+#endif
+
+  /* Begin the database scan
+  */
+  if( HasRowid(pTab) ){
+    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
+    pWInfo = sqlite3WhereBegin(
+        pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur
+    );
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+  
+    /* Remember the rowid of every item to be updated.
+    */
+    sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
+    if( !okOnePass ){
+      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+    }
+  
+    /* End the database scan loop.
+    */
+    sqlite3WhereEnd(pWInfo);
+  }else{
+    int iPk;         /* First of nPk memory cells holding PRIMARY KEY value */
+    i16 nPk;         /* Number of components of the PRIMARY KEY */
+    int addrOpen;    /* Address of the OpenEphemeral instruction */
+
+    assert( pPk!=0 );
+    nPk = pPk->nKeyCol;
+    iPk = pParse->nMem+1;
+    pParse->nMem += nPk;
+    regKey = ++pParse->nMem;
+    iEph = pParse->nTab++;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iPk);
+    addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk);
+    sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, 
+                               WHERE_ONEPASS_DESIRED, iIdxCur);
+    if( pWInfo==0 ) goto update_cleanup;
+    okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
+    for(i=0; i<nPk; i++){
+      assert( pPk->aiColumn[i]>=0 );
+      sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i],
+                                      iPk+i);
+    }
+    if( okOnePass ){
+      sqlite3VdbeChangeToNoop(v, addrOpen);
+      nKey = nPk;
+      regKey = iPk;
+    }else{
+      sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
+                        sqlite3IndexAffinityStr(db, pPk), nPk);
+      sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey);
+    }
+    sqlite3WhereEnd(pWInfo);
+  }
+
+  /* Initialize the count of updated rows
+  */
+  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){
+    regRowCount = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
+  }
+
+  labelBreak = sqlite3VdbeMakeLabel(v);
+  if( !isView ){
+    /* 
+    ** Open every index that needs updating.  Note that if any
+    ** index could potentially invoke a REPLACE conflict resolution 
+    ** action, then we need to open all indices because we might need
+    ** to be deleting some records.
+    */
+    if( onError==OE_Replace ){
+      memset(aToOpen, 1, nIdx+1);
+    }else{
+      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+        if( pIdx->onError==OE_Replace ){
+          memset(aToOpen, 1, nIdx+1);
+          break;
+        }
+      }
+    }
+    if( okOnePass ){
+      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
+      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
+    }
+    sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen,
+                               0, 0);
+  }
+
+  /* Top of the update loop */
+  if( okOnePass ){
+    if( aToOpen[iDataCur-iBaseCur] && !isView ){
+      assert( pPk );
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey);
+      VdbeCoverageNeverTaken(v);
+    }
+    labelContinue = labelBreak;
+    sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
+    VdbeCoverageIf(v, pPk==0);
+    VdbeCoverageIf(v, pPk!=0);
+  }else if( pPk ){
+    labelContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
+    addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey);
+    sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0);
+    VdbeCoverage(v);
+  }else{
+    labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak,
+                             regOldRowid);
+    VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+    VdbeCoverage(v);
+  }
+
+  /* If the record number will change, set register regNewRowid to
+  ** contain the new value. If the record number is not being modified,
+  ** then regNewRowid is the same register as regOldRowid, which is
+  ** already populated.  */
+  assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
+  if( chngRowid ){
+    sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
+    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
+  }
+
+  /* Compute the old pre-UPDATE content of the row being changed, if that
+  ** information is needed */
+  if( chngPk || hasFK || pTrigger ){
+    u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
+    oldmask |= sqlite3TriggerColmask(pParse, 
+        pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
+    );
+    for(i=0; i<pTab->nCol; i++){
+      if( oldmask==0xffffffff
+       || (i<32 && (oldmask & MASKBIT32(i))!=0)
+       || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0
+      ){
+        testcase(  oldmask!=0xffffffff && i==31 );
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
+      }
+    }
+    if( chngRowid==0 && pPk==0 ){
+      sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
+    }
+  }
+
+  /* Populate the array of registers beginning at regNew with the new
+  ** row data. This array is used to check constants, create the new
+  ** table and index records, and as the values for any new.* references
+  ** made by triggers.
+  **
+  ** If there are one or more BEFORE triggers, then do not populate the
+  ** registers associated with columns that are (a) not modified by
+  ** this UPDATE statement and (b) not accessed by new.* references. The
+  ** values for registers not modified by the UPDATE must be reloaded from 
+  ** the database after the BEFORE triggers are fired anyway (as the trigger 
+  ** may have modified them). So not loading those that are not going to
+  ** be used eliminates some redundant opcodes.
+  */
+  newmask = sqlite3TriggerColmask(
+      pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
+  );
+  for(i=0; i<pTab->nCol; i++){
+    if( i==pTab->iPKey ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
+    }else{
+      j = aXRef[i];
+      if( j>=0 ){
+        sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i);
+      }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
+        /* This branch loads the value of a column that will not be changed 
+        ** into a register. This is done if there are no BEFORE triggers, or
+        ** if there are one or more BEFORE triggers that use this value via
+        ** a new.* reference in a trigger program.
+        */
+        testcase( i==31 );
+        testcase( i==32 );
+        sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i);
+      }
+    }
+  }
+
+  /* Fire any BEFORE UPDATE triggers. This happens before constraints are
+  ** verified. One could argue that this is wrong.
+  */
+  if( tmask&TRIGGER_BEFORE ){
+    sqlite3TableAffinity(v, pTab, regNew);
+    sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
+        TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
+
+    /* The row-trigger may have deleted the row being updated. In this
+    ** case, jump to the next row. No updates or AFTER triggers are 
+    ** required. This behavior - what happens when the row being updated
+    ** is deleted or renamed by a BEFORE trigger - is left undefined in the
+    ** documentation.
+    */
+    if( pPk ){
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey);
+      VdbeCoverage(v);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
+      VdbeCoverage(v);
+    }
+
+    /* If it did not delete it, the row-trigger may still have modified 
+    ** some of the columns of the row being updated. Load the values for 
+    ** all columns not modified by the update statement into their 
+    ** registers in case this has happened.
+    */
+    for(i=0; i<pTab->nCol; i++){
+      if( aXRef[i]<0 && i!=pTab->iPKey ){
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i);
+      }
+    }
+  }
+
+  if( !isView ){
+    int addr1 = 0;        /* Address of jump instruction */
+    int bReplace = 0;     /* True if REPLACE conflict resolution might happen */
+
+    /* Do constraint checks. */
+    assert( regOldRowid>0 );
+    sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
+        regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace);
+
+    /* Do FK constraint checks. */
+    if( hasFK ){
+      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
+    }
+
+    /* Delete the index entries associated with the current record.  */
+    if( bReplace || chngKey ){
+      if( pPk ){
+        addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey);
+      }else{
+        addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
+      }
+      VdbeCoverageNeverTaken(v);
+    }
+    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
+  
+    /* If changing the record number, delete the old record.  */
+    if( hasFK || chngKey || pPk!=0 ){
+      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
+    }
+    if( bReplace || chngKey ){
+      sqlite3VdbeJumpHere(v, addr1);
+    }
+
+    if( hasFK ){
+      sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
+    }
+  
+    /* Insert the new index entries and the new record. */
+    sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
+                             regNewRowid, aRegIdx, 1, 0, 0);
+
+    /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
+    ** handle rows (possibly in other tables) that refer via a foreign key
+    ** to the row just updated. */ 
+    if( hasFK ){
+      sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
+    }
+  }
+
+  /* Increment the row counter 
+  */
+  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){
+    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
+  }
+
+  sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, 
+      TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
+
+  /* Repeat the above with the next record to be updated, until
+  ** all record selected by the WHERE clause have been updated.
+  */
+  if( okOnePass ){
+    /* Nothing to do at end-of-loop for a single-pass */
+  }else if( pPk ){
+    sqlite3VdbeResolveLabel(v, labelContinue);
+    sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
+  }else{
+    sqlite3VdbeGoto(v, labelContinue);
+  }
+  sqlite3VdbeResolveLabel(v, labelBreak);
+
+  /* Close all tables */
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
+    assert( aRegIdx );
+    if( aToOpen[i+1] ){
+      sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0);
+    }
+  }
+  if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0);
+
+  /* Update the sqlite_sequence table by storing the content of the
+  ** maximum rowid counter values recorded while inserting into
+  ** autoincrement tables.
+  */
+  if( pParse->nested==0 && pParse->pTriggerTab==0 ){
+    sqlite3AutoincrementEnd(pParse);
+  }
+
+  /*
+  ** Return the number of rows that were changed. If this routine is 
+  ** generating code because of a call to sqlite3NestedParse(), do not
+  ** invoke the callback function.
+  */
+  if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){
+    sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
+    sqlite3VdbeSetNumCols(v, 1);
+    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);
+  }
+
+update_cleanup:
+  sqlite3AuthContextPop(&sContext);
+  sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
+  sqlite3SrcListDelete(db, pTabList);
+  sqlite3ExprListDelete(db, pChanges);
+  sqlite3ExprDelete(db, pWhere);
+  return;
+}
+/* Make sure "isView" and other macros defined above are undefined. Otherwise
+** they may interfere with compilation of other functions in this file
+** (or in another file, if this file becomes part of the amalgamation).  */
+#ifdef isView
+ #undef isView
+#endif
+#ifdef pTrigger
+ #undef pTrigger
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Generate code for an UPDATE of a virtual table.
+**
+** There are two possible strategies - the default and the special 
+** "onepass" strategy. Onepass is only used if the virtual table 
+** implementation indicates that pWhere may match at most one row.
+**
+** The default strategy is to create an ephemeral table that contains
+** for each row to be changed:
+**
+**   (A)  The original rowid of that row.
+**   (B)  The revised rowid for the row.
+**   (C)  The content of every column in the row.
+**
+** Then loop through the contents of this ephemeral table executing a
+** VUpdate for each row. When finished, drop the ephemeral table.
+**
+** The "onepass" strategy does not use an ephemeral table. Instead, it
+** stores the same values (A, B and C above) in a register array and
+** makes a single invocation of VUpdate.
+*/
+static void updateVirtualTable(
+  Parse *pParse,       /* The parsing context */
+  SrcList *pSrc,       /* The virtual table to be modified */
+  Table *pTab,         /* The virtual table */
+  ExprList *pChanges,  /* The columns to change in the UPDATE statement */
+  Expr *pRowid,        /* Expression used to recompute the rowid */
+  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
+  Expr *pWhere,        /* WHERE clause of the UPDATE statement */
+  int onError          /* ON CONFLICT strategy */
+){
+  Vdbe *v = pParse->pVdbe;  /* Virtual machine under construction */
+  int ephemTab;             /* Table holding the result of the SELECT */
+  int i;                    /* Loop counter */
+  sqlite3 *db = pParse->db; /* Database connection */
+  const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
+  WhereInfo *pWInfo;
+  int nArg = 2 + pTab->nCol;      /* Number of arguments to VUpdate */
+  int regArg;                     /* First register in VUpdate arg array */
+  int regRec;                     /* Register in which to assemble record */
+  int regRowid;                   /* Register for ephem table rowid */
+  int iCsr = pSrc->a[0].iCursor;  /* Cursor used for virtual table scan */
+  int aDummy[2];                  /* Unused arg for sqlite3WhereOkOnePass() */
+  int bOnePass;                   /* True to use onepass strategy */
+  int addr;                       /* Address of OP_OpenEphemeral */
+
+  /* Allocate nArg registers to martial the arguments to VUpdate. Then
+  ** create and open the ephemeral table in which the records created from
+  ** these arguments will be temporarily stored. */
+  assert( v );
+  ephemTab = pParse->nTab++;
+  addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
+  regArg = pParse->nMem + 1;
+  pParse->nMem += nArg;
+  regRec = ++pParse->nMem;
+  regRowid = ++pParse->nMem;
+
+  /* Start scanning the virtual table */
+  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0);
+  if( pWInfo==0 ) return;
+
+  /* Populate the argument registers. */
+  sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
+  if( pRowid ){
+    sqlite3ExprCode(pParse, pRowid, regArg+1);
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
+  }
+  for(i=0; i<pTab->nCol; i++){
+    if( aXRef[i]>=0 ){
+      sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
+    }
+  }
+
+  bOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);
+
+  if( bOnePass ){
+    /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
+    ** above. Also, if this is a top-level parse (not a trigger), clear the
+    ** multi-write flag so that the VM does not open a statement journal */
+    sqlite3VdbeChangeToNoop(v, addr);
+    if( sqlite3IsToplevel(pParse) ){
+      pParse->isMultiWrite = 0;
+    }
+  }else{
+    /* Create a record from the argument register contents and insert it into
+    ** the ephemeral table. */
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);
+  }
+
+
+  if( bOnePass==0 ){
+    /* End the virtual table scan */
+    sqlite3WhereEnd(pWInfo);
+
+    /* Begin scannning through the ephemeral table. */
+    addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);
+
+    /* Extract arguments from the current row of the ephemeral table and 
+    ** invoke the VUpdate method.  */
+    for(i=0; i<nArg; i++){
+      sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);
+    }
+  }
+  sqlite3VtabMakeWritable(pParse, pTab);
+  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
+  sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
+  sqlite3MayAbort(pParse);
+
+  /* End of the ephemeral table scan. Or, if using the onepass strategy,
+  ** jump to here if the scan visited zero rows. */
+  if( bOnePass==0 ){
+    sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr);
+    sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
+  }else{
+    sqlite3WhereEnd(pWInfo);
+  }
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/************** End of update.c **********************************************/
+/************** Begin file vacuum.c ******************************************/
+/*
+** 2003 April 6
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to implement the VACUUM command.
+**
+** Most of the code in this file may be omitted by defining the
+** SQLITE_OMIT_VACUUM macro.
+*/
+/* #include "sqliteInt.h" */
+/* #include "vdbeInt.h" */
+
+#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
+/*
+** Finalize a prepared statement.  If there was an error, store the
+** text of the error message in *pzErrMsg.  Return the result code.
+*/
+static int vacuumFinalize(sqlite3 *db, sqlite3_stmt *pStmt, char **pzErrMsg){
+  int rc;
+  rc = sqlite3VdbeFinalize((Vdbe*)pStmt);
+  if( rc ){
+    sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
+  }
+  return rc;
+}
+
+/*
+** Execute zSql on database db. Return an error code.
+*/
+static int execSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
+  sqlite3_stmt *pStmt;
+  VVA_ONLY( int rc; )
+  if( !zSql ){
+    return SQLITE_NOMEM;
+  }
+  if( SQLITE_OK!=sqlite3_prepare(db, zSql, -1, &pStmt, 0) ){
+    sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
+    return sqlite3_errcode(db);
+  }
+  VVA_ONLY( rc = ) sqlite3_step(pStmt);
+  assert( rc!=SQLITE_ROW || (db->flags&SQLITE_CountRows) );
+  return vacuumFinalize(db, pStmt, pzErrMsg);
+}
+
+/*
+** Execute zSql on database db. The statement returns exactly
+** one column. Execute this as SQL on the same database.
+*/
+static int execExecSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+
+  while( SQLITE_ROW==sqlite3_step(pStmt) ){
+    rc = execSql(db, pzErrMsg, (char*)sqlite3_column_text(pStmt, 0));
+    if( rc!=SQLITE_OK ){
+      vacuumFinalize(db, pStmt, pzErrMsg);
+      return rc;
+    }
+  }
+
+  return vacuumFinalize(db, pStmt, pzErrMsg);
+}
+
+/*
+** The VACUUM command is used to clean up the database,
+** collapse free space, etc.  It is modelled after the VACUUM command
+** in PostgreSQL.  The VACUUM command works as follows:
+**
+**   (1)  Create a new transient database file
+**   (2)  Copy all content from the database being vacuumed into
+**        the new transient database file
+**   (3)  Copy content from the transient database back into the
+**        original database.
+**
+** The transient database requires temporary disk space approximately
+** equal to the size of the original database.  The copy operation of
+** step (3) requires additional temporary disk space approximately equal
+** to the size of the original database for the rollback journal.
+** Hence, temporary disk space that is approximately 2x the size of the
+** original database is required.  Every page of the database is written
+** approximately 3 times:  Once for step (2) and twice for step (3).
+** Two writes per page are required in step (3) because the original
+** database content must be written into the rollback journal prior to
+** overwriting the database with the vacuumed content.
+**
+** Only 1x temporary space and only 1x writes would be required if
+** the copy of step (3) were replaced by deleting the original database
+** and renaming the transient database as the original.  But that will
+** not work if other processes are attached to the original database.
+** And a power loss in between deleting the original and renaming the
+** transient would cause the database file to appear to be deleted
+** following reboot.
+*/
+SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse){
+  Vdbe *v = sqlite3GetVdbe(pParse);
+  if( v ){
+    sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
+    sqlite3VdbeUsesBtree(v, 0);
+  }
+  return;
+}
+
+/*
+** This routine implements the OP_Vacuum opcode of the VDBE.
+*/
+SQLITE_PRIVATE int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
+  int rc = SQLITE_OK;     /* Return code from service routines */
+  Btree *pMain;           /* The database being vacuumed */
+  Btree *pTemp;           /* The temporary database we vacuum into */
+  char *zSql = 0;         /* SQL statements */
+  int saved_flags;        /* Saved value of the db->flags */
+  int saved_nChange;      /* Saved value of db->nChange */
+  int saved_nTotalChange; /* Saved value of db->nTotalChange */
+  void (*saved_xTrace)(void*,const char*);  /* Saved db->xTrace */
+  Db *pDb = 0;            /* Database to detach at end of vacuum */
+  int isMemDb;            /* True if vacuuming a :memory: database */
+  int nRes;               /* Bytes of reserved space at the end of each page */
+  int nDb;                /* Number of attached databases */
+
+  if( !db->autoCommit ){
+    sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
+    return SQLITE_ERROR;
+  }
+  if( db->nVdbeActive>1 ){
+    sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");
+    return SQLITE_ERROR;
+  }
+
+  /* Save the current value of the database flags so that it can be 
+  ** restored before returning. Then set the writable-schema flag, and
+  ** disable CHECK and foreign key constraints.  */
+  saved_flags = db->flags;
+  saved_nChange = db->nChange;
+  saved_nTotalChange = db->nTotalChange;
+  saved_xTrace = db->xTrace;
+  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks | SQLITE_PreferBuiltin;
+  db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder);
+  db->xTrace = 0;
+
+  pMain = db->aDb[0].pBt;
+  isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
+
+  /* Attach the temporary database as 'vacuum_db'. The synchronous pragma
+  ** can be set to 'off' for this file, as it is not recovered if a crash
+  ** occurs anyway. The integrity of the database is maintained by a
+  ** (possibly synchronous) transaction opened on the main database before
+  ** sqlite3BtreeCopyFile() is called.
+  **
+  ** An optimisation would be to use a non-journaled pager.
+  ** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
+  ** that actually made the VACUUM run slower.  Very little journalling
+  ** actually occurs when doing a vacuum since the vacuum_db is initially
+  ** empty.  Only the journal header is written.  Apparently it takes more
+  ** time to parse and run the PRAGMA to turn journalling off than it does
+  ** to write the journal header file.
+  */
+  nDb = db->nDb;
+  if( sqlite3TempInMemory(db) ){
+    zSql = "ATTACH ':memory:' AS vacuum_db;";
+  }else{
+    zSql = "ATTACH '' AS vacuum_db;";
+  }
+  rc = execSql(db, pzErrMsg, zSql);
+  if( db->nDb>nDb ){
+    pDb = &db->aDb[db->nDb-1];
+    assert( strcmp(pDb->zName,"vacuum_db")==0 );
+  }
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  pTemp = db->aDb[db->nDb-1].pBt;
+
+  /* The call to execSql() to attach the temp database has left the file
+  ** locked (as there was more than one active statement when the transaction
+  ** to read the schema was concluded. Unlock it here so that this doesn't
+  ** cause problems for the call to BtreeSetPageSize() below.  */
+  sqlite3BtreeCommit(pTemp);
+
+  nRes = sqlite3BtreeGetOptimalReserve(pMain);
+
+  /* A VACUUM cannot change the pagesize of an encrypted database. */
+#ifdef SQLITE_HAS_CODEC
+  if( db->nextPagesize ){
+    extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
+    int nKey;
+    char *zKey;
+    sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
+    if( nKey ) db->nextPagesize = 0;
+  }
+#endif
+
+  rc = execSql(db, pzErrMsg, "PRAGMA vacuum_db.synchronous=OFF");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Begin a transaction and take an exclusive lock on the main database
+  ** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
+  ** to ensure that we do not try to change the page-size on a WAL database.
+  */
+  rc = execSql(db, pzErrMsg, "BEGIN;");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = sqlite3BtreeBeginTrans(pMain, 2);
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Do not attempt to change the page size for a WAL database */
+  if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
+                                               ==PAGER_JOURNALMODE_WAL ){
+    db->nextPagesize = 0;
+  }
+
+  if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
+   || (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
+   || NEVER(db->mallocFailed)
+  ){
+    rc = SQLITE_NOMEM;
+    goto end_of_vacuum;
+  }
+
+#ifndef SQLITE_OMIT_AUTOVACUUM
+  sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
+                                           sqlite3BtreeGetAutoVacuum(pMain));
+#endif
+
+  /* Query the schema of the main database. Create a mirror schema
+  ** in the temporary database.
+  */
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
+      "  FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
+      "   AND coalesce(rootpage,1)>0"
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14)"
+      "  FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21) "
+      "  FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Loop through the tables in the main database. For each, do
+  ** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
+  ** the contents to the temporary database.
+  */
+  assert( (db->flags & SQLITE_Vacuum)==0 );
+  db->flags |= SQLITE_Vacuum;
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
+      "|| ' SELECT * FROM main.' || quote(name) || ';'"
+      "FROM main.sqlite_master "
+      "WHERE type = 'table' AND name!='sqlite_sequence' "
+      "  AND coalesce(rootpage,1)>0"
+  );
+  assert( (db->flags & SQLITE_Vacuum)!=0 );
+  db->flags &= ~SQLITE_Vacuum;
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+  /* Copy over the sequence table
+  */
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
+      "FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+  rc = execExecSql(db, pzErrMsg,
+      "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
+      "|| ' SELECT * FROM main.' || quote(name) || ';' "
+      "FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
+  );
+  if( rc!=SQLITE_OK ) goto end_of_vacuum;
+
+
+  /* Copy the triggers, views, and virtual tables from the main database
+  ** over to the temporary database.  None of these objects has any
+  ** associated storage, so all we have to do is copy their entries
+  ** from the SQLITE_MASTER table.
+  */
+  rc = execSql(db, pzErrMsg,
+      "INSERT INTO vacuum_db.sqlite_master "
+      "  SELECT type, name, tbl_name, rootpage, sql"
+      "    FROM main.sqlite_master"
+      "   WHERE type='view' OR type='trigger'"
+      "      OR (type='table' AND rootpage=0)"
+  );
+  if( rc ) goto end_of_vacuum;
+
+  /* At this point, there is a write transaction open on both the 
+  ** vacuum database and the main database. Assuming no error occurs,
+  ** both transactions are closed by this block - the main database
+  ** transaction by sqlite3BtreeCopyFile() and the other by an explicit
+  ** call to sqlite3BtreeCommit().
+  */
+  {
+    u32 meta;
+    int i;
+
+    /* This array determines which meta meta values are preserved in the
+    ** vacuum.  Even entries are the meta value number and odd entries
+    ** are an increment to apply to the meta value after the vacuum.
+    ** The increment is used to increase the schema cookie so that other
+    ** connections to the same database will know to reread the schema.
+    */
+    static const unsigned char aCopy[] = {
+       BTREE_SCHEMA_VERSION,     1,  /* Add one to the old schema cookie */
+       BTREE_DEFAULT_CACHE_SIZE, 0,  /* Preserve the default page cache size */
+       BTREE_TEXT_ENCODING,      0,  /* Preserve the text encoding */
+       BTREE_USER_VERSION,       0,  /* Preserve the user version */
+       BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
+    };
+
+    assert( 1==sqlite3BtreeIsInTrans(pTemp) );
+    assert( 1==sqlite3BtreeIsInTrans(pMain) );
+
+    /* Copy Btree meta values */
+    for(i=0; i<ArraySize(aCopy); i+=2){
+      /* GetMeta() and UpdateMeta() cannot fail in this context because
+      ** we already have page 1 loaded into cache and marked dirty. */
+      sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
+      rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
+      if( NEVER(rc!=SQLITE_OK) ) goto end_of_vacuum;
+    }
+
+    rc = sqlite3BtreeCopyFile(pMain, pTemp);
+    if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    rc = sqlite3BtreeCommit(pTemp);
+    if( rc!=SQLITE_OK ) goto end_of_vacuum;
+#ifndef SQLITE_OMIT_AUTOVACUUM
+    sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
+#endif
+  }
+
+  assert( rc==SQLITE_OK );
+  rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes,1);
+
+end_of_vacuum:
+  /* Restore the original value of db->flags */
+  db->flags = saved_flags;
+  db->nChange = saved_nChange;
+  db->nTotalChange = saved_nTotalChange;
+  db->xTrace = saved_xTrace;
+  sqlite3BtreeSetPageSize(pMain, -1, -1, 1);
+
+  /* Currently there is an SQL level transaction open on the vacuum
+  ** database. No locks are held on any other files (since the main file
+  ** was committed at the btree level). So it safe to end the transaction
+  ** by manually setting the autoCommit flag to true and detaching the
+  ** vacuum database. The vacuum_db journal file is deleted when the pager
+  ** is closed by the DETACH.
+  */
+  db->autoCommit = 1;
+
+  if( pDb ){
+    sqlite3BtreeClose(pDb->pBt);
+    pDb->pBt = 0;
+    pDb->pSchema = 0;
+  }
+
+  /* This both clears the schemas and reduces the size of the db->aDb[]
+  ** array. */ 
+  sqlite3ResetAllSchemasOfConnection(db);
+
+  return rc;
+}
+
+#endif  /* SQLITE_OMIT_VACUUM && SQLITE_OMIT_ATTACH */
+
+/************** End of vacuum.c **********************************************/
+/************** Begin file vtab.c ********************************************/
+/*
+** 2006 June 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code used to help implement virtual tables.
+*/
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* #include "sqliteInt.h" */
+
+/*
+** Before a virtual table xCreate() or xConnect() method is invoked, the
+** sqlite3.pVtabCtx member variable is set to point to an instance of
+** this struct allocated on the stack. It is used by the implementation of 
+** the sqlite3_declare_vtab() and sqlite3_vtab_config() APIs, both of which
+** are invoked only from within xCreate and xConnect methods.
+*/
+struct VtabCtx {
+  VTable *pVTable;    /* The virtual table being constructed */
+  Table *pTab;        /* The Table object to which the virtual table belongs */
+  VtabCtx *pPrior;    /* Parent context (if any) */
+  int bDeclared;      /* True after sqlite3_declare_vtab() is called */
+};
+
+/*
+** The actual function that does the work of creating a new module.
+** This function implements the sqlite3_create_module() and
+** sqlite3_create_module_v2() interfaces.
+*/
+static int createModule(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+){
+  int rc = SQLITE_OK;
+  int nName;
+
+  sqlite3_mutex_enter(db->mutex);
+  nName = sqlite3Strlen30(zName);
+  if( sqlite3HashFind(&db->aModule, zName) ){
+    rc = SQLITE_MISUSE_BKPT;
+  }else{
+    Module *pMod;
+    pMod = (Module *)sqlite3DbMallocRaw(db, sizeof(Module) + nName + 1);
+    if( pMod ){
+      Module *pDel;
+      char *zCopy = (char *)(&pMod[1]);
+      memcpy(zCopy, zName, nName+1);
+      pMod->zName = zCopy;
+      pMod->pModule = pModule;
+      pMod->pAux = pAux;
+      pMod->xDestroy = xDestroy;
+      pMod->pEpoTab = 0;
+      pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
+      assert( pDel==0 || pDel==pMod );
+      if( pDel ){
+        db->mallocFailed = 1;
+        sqlite3DbFree(db, pDel);
+      }
+    }
+  }
+  rc = sqlite3ApiExit(db, rc);
+  if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
+
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+
+/*
+** External API function used to create a new virtual-table module.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux                      /* Context pointer for xCreate/xConnect */
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  return createModule(db, zName, pModule, pAux, 0);
+}
+
+/*
+** External API function used to create a new virtual-table module.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
+  sqlite3 *db,                    /* Database in which module is registered */
+  const char *zName,              /* Name assigned to this module */
+  const sqlite3_module *pModule,  /* The definition of the module */
+  void *pAux,                     /* Context pointer for xCreate/xConnect */
+  void (*xDestroy)(void *)        /* Module destructor function */
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  return createModule(db, zName, pModule, pAux, xDestroy);
+}
+
+/*
+** Lock the virtual table so that it cannot be disconnected.
+** Locks nest.  Every lock should have a corresponding unlock.
+** If an unlock is omitted, resources leaks will occur.  
+**
+** If a disconnect is attempted while a virtual table is locked,
+** the disconnect is deferred until all locks have been removed.
+*/
+SQLITE_PRIVATE void sqlite3VtabLock(VTable *pVTab){
+  pVTab->nRef++;
+}
+
+
+/*
+** pTab is a pointer to a Table structure representing a virtual-table.
+** Return a pointer to the VTable object used by connection db to access 
+** this virtual-table, if one has been created, or NULL otherwise.
+*/
+SQLITE_PRIVATE VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){
+  VTable *pVtab;
+  assert( IsVirtual(pTab) );
+  for(pVtab=pTab->pVTable; pVtab && pVtab->db!=db; pVtab=pVtab->pNext);
+  return pVtab;
+}
+
+/*
+** Decrement the ref-count on a virtual table object. When the ref-count
+** reaches zero, call the xDisconnect() method to delete the object.
+*/
+SQLITE_PRIVATE void sqlite3VtabUnlock(VTable *pVTab){
+  sqlite3 *db = pVTab->db;
+
+  assert( db );
+  assert( pVTab->nRef>0 );
+  assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE );
+
+  pVTab->nRef--;
+  if( pVTab->nRef==0 ){
+    sqlite3_vtab *p = pVTab->pVtab;
+    if( p ){
+      p->pModule->xDisconnect(p);
+    }
+    sqlite3DbFree(db, pVTab);
+  }
+}
+
+/*
+** Table p is a virtual table. This function moves all elements in the
+** p->pVTable list to the sqlite3.pDisconnect lists of their associated
+** database connections to be disconnected at the next opportunity. 
+** Except, if argument db is not NULL, then the entry associated with
+** connection db is left in the p->pVTable list.
+*/
+static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){
+  VTable *pRet = 0;
+  VTable *pVTable = p->pVTable;
+  p->pVTable = 0;
+
+  /* Assert that the mutex (if any) associated with the BtShared database 
+  ** that contains table p is held by the caller. See header comments 
+  ** above function sqlite3VtabUnlockList() for an explanation of why
+  ** this makes it safe to access the sqlite3.pDisconnect list of any
+  ** database connection that may have an entry in the p->pVTable list.
+  */
+  assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
+
+  while( pVTable ){
+    sqlite3 *db2 = pVTable->db;
+    VTable *pNext = pVTable->pNext;
+    assert( db2 );
+    if( db2==db ){
+      pRet = pVTable;
+      p->pVTable = pRet;
+      pRet->pNext = 0;
+    }else{
+      pVTable->pNext = db2->pDisconnect;
+      db2->pDisconnect = pVTable;
+    }
+    pVTable = pNext;
+  }
+
+  assert( !db || pRet );
+  return pRet;
+}
+
+/*
+** Table *p is a virtual table. This function removes the VTable object
+** for table *p associated with database connection db from the linked
+** list in p->pVTab. It also decrements the VTable ref count. This is
+** used when closing database connection db to free all of its VTable
+** objects without disturbing the rest of the Schema object (which may
+** be being used by other shared-cache connections).
+*/
+SQLITE_PRIVATE void sqlite3VtabDisconnect(sqlite3 *db, Table *p){
+  VTable **ppVTab;
+
+  assert( IsVirtual(p) );
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){
+    if( (*ppVTab)->db==db  ){
+      VTable *pVTab = *ppVTab;
+      *ppVTab = pVTab->pNext;
+      sqlite3VtabUnlock(pVTab);
+      break;
+    }
+  }
+}
+
+
+/*
+** Disconnect all the virtual table objects in the sqlite3.pDisconnect list.
+**
+** This function may only be called when the mutexes associated with all
+** shared b-tree databases opened using connection db are held by the 
+** caller. This is done to protect the sqlite3.pDisconnect list. The
+** sqlite3.pDisconnect list is accessed only as follows:
+**
+**   1) By this function. In this case, all BtShared mutexes and the mutex
+**      associated with the database handle itself must be held.
+**
+**   2) By function vtabDisconnectAll(), when it adds a VTable entry to
+**      the sqlite3.pDisconnect list. In this case either the BtShared mutex
+**      associated with the database the virtual table is stored in is held
+**      or, if the virtual table is stored in a non-sharable database, then
+**      the database handle mutex is held.
+**
+** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously 
+** by multiple threads. It is thread-safe.
+*/
+SQLITE_PRIVATE void sqlite3VtabUnlockList(sqlite3 *db){
+  VTable *p = db->pDisconnect;
+  db->pDisconnect = 0;
+
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  if( p ){
+    sqlite3ExpirePreparedStatements(db);
+    do {
+      VTable *pNext = p->pNext;
+      sqlite3VtabUnlock(p);
+      p = pNext;
+    }while( p );
+  }
+}
+
+/*
+** Clear any and all virtual-table information from the Table record.
+** This routine is called, for example, just before deleting the Table
+** record.
+**
+** Since it is a virtual-table, the Table structure contains a pointer
+** to the head of a linked list of VTable structures. Each VTable 
+** structure is associated with a single sqlite3* user of the schema.
+** The reference count of the VTable structure associated with database 
+** connection db is decremented immediately (which may lead to the 
+** structure being xDisconnected and free). Any other VTable structures
+** in the list are moved to the sqlite3.pDisconnect list of the associated 
+** database connection.
+*/
+SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){
+  if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p);
+  if( p->azModuleArg ){
+    int i;
+    for(i=0; i<p->nModuleArg; i++){
+      if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]);
+    }
+    sqlite3DbFree(db, p->azModuleArg);
+  }
+}
+
+/*
+** Add a new module argument to pTable->azModuleArg[].
+** The string is not copied - the pointer is stored.  The
+** string will be freed automatically when the table is
+** deleted.
+*/
+static void addModuleArgument(sqlite3 *db, Table *pTable, char *zArg){
+  int nBytes = sizeof(char *)*(2+pTable->nModuleArg);
+  char **azModuleArg;
+  azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
+  if( azModuleArg==0 ){
+    sqlite3DbFree(db, zArg);
+  }else{
+    int i = pTable->nModuleArg++;
+    azModuleArg[i] = zArg;
+    azModuleArg[i+1] = 0;
+    pTable->azModuleArg = azModuleArg;
+  }
+}
+
+/*
+** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
+** statement.  The module name has been parsed, but the optional list
+** of parameters that follow the module name are still pending.
+*/
+SQLITE_PRIVATE void sqlite3VtabBeginParse(
+  Parse *pParse,        /* Parsing context */
+  Token *pName1,        /* Name of new table, or database name */
+  Token *pName2,        /* Name of new table or NULL */
+  Token *pModuleName,   /* Name of the module for the virtual table */
+  int ifNotExists       /* No error if the table already exists */
+){
+  int iDb;              /* The database the table is being created in */
+  Table *pTable;        /* The new virtual table */
+  sqlite3 *db;          /* Database connection */
+
+  sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists);
+  pTable = pParse->pNewTable;
+  if( pTable==0 ) return;
+  assert( 0==pTable->pIndex );
+
+  db = pParse->db;
+  iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
+  assert( iDb>=0 );
+
+  pTable->tabFlags |= TF_Virtual;
+  pTable->nModuleArg = 0;
+  addModuleArgument(db, pTable, sqlite3NameFromToken(db, pModuleName));
+  addModuleArgument(db, pTable, 0);
+  addModuleArgument(db, pTable, sqlite3DbStrDup(db, pTable->zName));
+  assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)
+       || (pParse->sNameToken.z==pName1->z && pName2->z==0)
+  );
+  pParse->sNameToken.n = (int)(
+      &pModuleName->z[pModuleName->n] - pParse->sNameToken.z
+  );
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  /* Creating a virtual table invokes the authorization callback twice.
+  ** The first invocation, to obtain permission to INSERT a row into the
+  ** sqlite_master table, has already been made by sqlite3StartTable().
+  ** The second call, to obtain permission to create the table, is made now.
+  */
+  if( pTable->azModuleArg ){
+    sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName, 
+            pTable->azModuleArg[0], pParse->db->aDb[iDb].zName);
+  }
+#endif
+}
+
+/*
+** This routine takes the module argument that has been accumulating
+** in pParse->zArg[] and appends it to the list of arguments on the
+** virtual table currently under construction in pParse->pTable.
+*/
+static void addArgumentToVtab(Parse *pParse){
+  if( pParse->sArg.z && pParse->pNewTable ){
+    const char *z = (const char*)pParse->sArg.z;
+    int n = pParse->sArg.n;
+    sqlite3 *db = pParse->db;
+    addModuleArgument(db, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));
+  }
+}
+
+/*
+** The parser calls this routine after the CREATE VIRTUAL TABLE statement
+** has been completely parsed.
+*/
+SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
+  Table *pTab = pParse->pNewTable;  /* The table being constructed */
+  sqlite3 *db = pParse->db;         /* The database connection */
+
+  if( pTab==0 ) return;
+  addArgumentToVtab(pParse);
+  pParse->sArg.z = 0;
+  if( pTab->nModuleArg<1 ) return;
+  
+  /* If the CREATE VIRTUAL TABLE statement is being entered for the
+  ** first time (in other words if the virtual table is actually being
+  ** created now instead of just being read out of sqlite_master) then
+  ** do additional initialization work and store the statement text
+  ** in the sqlite_master table.
+  */
+  if( !db->init.busy ){
+    char *zStmt;
+    char *zWhere;
+    int iDb;
+    int iReg;
+    Vdbe *v;
+
+    /* Compute the complete text of the CREATE VIRTUAL TABLE statement */
+    if( pEnd ){
+      pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;
+    }
+    zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
+
+    /* A slot for the record has already been allocated in the 
+    ** SQLITE_MASTER table.  We just need to update that slot with all
+    ** the information we've collected.  
+    **
+    ** The VM register number pParse->regRowid holds the rowid of an
+    ** entry in the sqlite_master table tht was created for this vtab
+    ** by sqlite3StartTable().
+    */
+    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    sqlite3NestedParse(pParse,
+      "UPDATE %Q.%s "
+         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
+       "WHERE rowid=#%d",
+      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
+      pTab->zName,
+      pTab->zName,
+      zStmt,
+      pParse->regRowid
+    );
+    sqlite3DbFree(db, zStmt);
+    v = sqlite3GetVdbe(pParse);
+    sqlite3ChangeCookie(pParse, iDb);
+
+    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
+    zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
+    sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
+
+    iReg = ++pParse->nMem;
+    sqlite3VdbeLoadString(v, iReg, pTab->zName);
+    sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
+  }
+
+  /* If we are rereading the sqlite_master table create the in-memory
+  ** record of the table. The xConnect() method is not called until
+  ** the first time the virtual table is used in an SQL statement. This
+  ** allows a schema that contains virtual tables to be loaded before
+  ** the required virtual table implementations are registered.  */
+  else {
+    Table *pOld;
+    Schema *pSchema = pTab->pSchema;
+    const char *zName = pTab->zName;
+    assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
+    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
+    if( pOld ){
+      db->mallocFailed = 1;
+      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
+      return;
+    }
+    pParse->pNewTable = 0;
+  }
+}
+
+/*
+** The parser calls this routine when it sees the first token
+** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
+*/
+SQLITE_PRIVATE void sqlite3VtabArgInit(Parse *pParse){
+  addArgumentToVtab(pParse);
+  pParse->sArg.z = 0;
+  pParse->sArg.n = 0;
+}
+
+/*
+** The parser calls this routine for each token after the first token
+** in an argument to the module name in a CREATE VIRTUAL TABLE statement.
+*/
+SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse *pParse, Token *p){
+  Token *pArg = &pParse->sArg;
+  if( pArg->z==0 ){
+    pArg->z = p->z;
+    pArg->n = p->n;
+  }else{
+    assert(pArg->z <= p->z);
+    pArg->n = (int)(&p->z[p->n] - pArg->z);
+  }
+}
+
+/*
+** Invoke a virtual table constructor (either xCreate or xConnect). The
+** pointer to the function to invoke is passed as the fourth parameter
+** to this procedure.
+*/
+static int vtabCallConstructor(
+  sqlite3 *db, 
+  Table *pTab,
+  Module *pMod,
+  int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
+  char **pzErr
+){
+  VtabCtx sCtx;
+  VTable *pVTable;
+  int rc;
+  const char *const*azArg = (const char *const*)pTab->azModuleArg;
+  int nArg = pTab->nModuleArg;
+  char *zErr = 0;
+  char *zModuleName;
+  int iDb;
+  VtabCtx *pCtx;
+
+  /* Check that the virtual-table is not already being initialized */
+  for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){
+    if( pCtx->pTab==pTab ){
+      *pzErr = sqlite3MPrintf(db, 
+          "vtable constructor called recursively: %s", pTab->zName
+      );
+      return SQLITE_LOCKED;
+    }
+  }
+
+  zModuleName = sqlite3MPrintf(db, "%s", pTab->zName);
+  if( !zModuleName ){
+    return SQLITE_NOMEM;
+  }
+
+  pVTable = sqlite3DbMallocZero(db, sizeof(VTable));
+  if( !pVTable ){
+    sqlite3DbFree(db, zModuleName);
+    return SQLITE_NOMEM;
+  }
+  pVTable->db = db;
+  pVTable->pMod = pMod;
+
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  pTab->azModuleArg[1] = db->aDb[iDb].zName;
+
+  /* Invoke the virtual table constructor */
+  assert( &db->pVtabCtx );
+  assert( xConstruct );
+  sCtx.pTab = pTab;
+  sCtx.pVTable = pVTable;
+  sCtx.pPrior = db->pVtabCtx;
+  sCtx.bDeclared = 0;
+  db->pVtabCtx = &sCtx;
+  rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
+  db->pVtabCtx = sCtx.pPrior;
+  if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+  assert( sCtx.pTab==pTab );
+
+  if( SQLITE_OK!=rc ){
+    if( zErr==0 ){
+      *pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
+    }else {
+      *pzErr = sqlite3MPrintf(db, "%s", zErr);
+      sqlite3_free(zErr);
+    }
+    sqlite3DbFree(db, pVTable);
+  }else if( ALWAYS(pVTable->pVtab) ){
+    /* Justification of ALWAYS():  A correct vtab constructor must allocate
+    ** the sqlite3_vtab object if successful.  */
+    memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));
+    pVTable->pVtab->pModule = pMod->pModule;
+    pVTable->nRef = 1;
+    if( sCtx.bDeclared==0 ){
+      const char *zFormat = "vtable constructor did not declare schema: %s";
+      *pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
+      sqlite3VtabUnlock(pVTable);
+      rc = SQLITE_ERROR;
+    }else{
+      int iCol;
+      u8 oooHidden = 0;
+      /* If everything went according to plan, link the new VTable structure
+      ** into the linked list headed by pTab->pVTable. Then loop through the 
+      ** columns of the table to see if any of them contain the token "hidden".
+      ** If so, set the Column COLFLAG_HIDDEN flag and remove the token from
+      ** the type string.  */
+      pVTable->pNext = pTab->pVTable;
+      pTab->pVTable = pVTable;
+
+      for(iCol=0; iCol<pTab->nCol; iCol++){
+        char *zType = pTab->aCol[iCol].zType;
+        int nType;
+        int i = 0;
+        if( !zType ){
+          pTab->tabFlags |= oooHidden;
+          continue;
+        }
+        nType = sqlite3Strlen30(zType);
+        if( sqlite3StrNICmp("hidden", zType, 6)||(zType[6] && zType[6]!=' ') ){
+          for(i=0; i<nType; i++){
+            if( (0==sqlite3StrNICmp(" hidden", &zType[i], 7))
+             && (zType[i+7]=='\0' || zType[i+7]==' ')
+            ){
+              i++;
+              break;
+            }
+          }
+        }
+        if( i<nType ){
+          int j;
+          int nDel = 6 + (zType[i+6] ? 1 : 0);
+          for(j=i; (j+nDel)<=nType; j++){
+            zType[j] = zType[j+nDel];
+          }
+          if( zType[i]=='\0' && i>0 ){
+            assert(zType[i-1]==' ');
+            zType[i-1] = '\0';
+          }
+          pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN;
+          oooHidden = TF_OOOHidden;
+        }else{
+          pTab->tabFlags |= oooHidden;
+        }
+      }
+    }
+  }
+
+  sqlite3DbFree(db, zModuleName);
+  return rc;
+}
+
+/*
+** This function is invoked by the parser to call the xConnect() method
+** of the virtual table pTab. If an error occurs, an error code is returned 
+** and an error left in pParse.
+**
+** This call is a no-op if table pTab is not a virtual table.
+*/
+SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
+  sqlite3 *db = pParse->db;
+  const char *zMod;
+  Module *pMod;
+  int rc;
+
+  assert( pTab );
+  if( (pTab->tabFlags & TF_Virtual)==0 || sqlite3GetVTable(db, pTab) ){
+    return SQLITE_OK;
+  }
+
+  /* Locate the required virtual table module */
+  zMod = pTab->azModuleArg[0];
+  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
+
+  if( !pMod ){
+    const char *zModule = pTab->azModuleArg[0];
+    sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
+    rc = SQLITE_ERROR;
+  }else{
+    char *zErr = 0;
+    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
+    if( rc!=SQLITE_OK ){
+      sqlite3ErrorMsg(pParse, "%s", zErr);
+    }
+    sqlite3DbFree(db, zErr);
+  }
+
+  return rc;
+}
+/*
+** Grow the db->aVTrans[] array so that there is room for at least one
+** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise.
+*/
+static int growVTrans(sqlite3 *db){
+  const int ARRAY_INCR = 5;
+
+  /* Grow the sqlite3.aVTrans array if required */
+  if( (db->nVTrans%ARRAY_INCR)==0 ){
+    VTable **aVTrans;
+    int nBytes = sizeof(sqlite3_vtab *) * (db->nVTrans + ARRAY_INCR);
+    aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
+    if( !aVTrans ){
+      return SQLITE_NOMEM;
+    }
+    memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
+    db->aVTrans = aVTrans;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should
+** have already been reserved using growVTrans().
+*/
+static void addToVTrans(sqlite3 *db, VTable *pVTab){
+  /* Add pVtab to the end of sqlite3.aVTrans */
+  db->aVTrans[db->nVTrans++] = pVTab;
+  sqlite3VtabLock(pVTab);
+}
+
+/*
+** This function is invoked by the vdbe to call the xCreate method
+** of the virtual table named zTab in database iDb. 
+**
+** If an error occurs, *pzErr is set to point an an English language
+** description of the error and an SQLITE_XXX error code is returned.
+** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
+*/
+SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
+  int rc = SQLITE_OK;
+  Table *pTab;
+  Module *pMod;
+  const char *zMod;
+
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
+  assert( pTab && (pTab->tabFlags & TF_Virtual)!=0 && !pTab->pVTable );
+
+  /* Locate the required virtual table module */
+  zMod = pTab->azModuleArg[0];
+  pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
+
+  /* If the module has been registered and includes a Create method, 
+  ** invoke it now. If the module has not been registered, return an 
+  ** error. Otherwise, do nothing.
+  */
+  if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
+    *pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
+    rc = SQLITE_ERROR;
+  }else{
+    rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
+  }
+
+  /* Justification of ALWAYS():  The xConstructor method is required to
+  ** create a valid sqlite3_vtab if it returns SQLITE_OK. */
+  if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){
+    rc = growVTrans(db);
+    if( rc==SQLITE_OK ){
+      addToVTrans(db, sqlite3GetVTable(db, pTab));
+    }
+  }
+
+  return rc;
+}
+
+/*
+** This function is used to set the schema of a virtual table.  It is only
+** valid to call this function from within the xCreate() or xConnect() of a
+** virtual table module.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
+  VtabCtx *pCtx;
+  Parse *pParse;
+  int rc = SQLITE_OK;
+  Table *pTab;
+  char *zErr = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pCtx = db->pVtabCtx;
+  if( !pCtx || pCtx->bDeclared ){
+    sqlite3Error(db, SQLITE_MISUSE);
+    sqlite3_mutex_leave(db->mutex);
+    return SQLITE_MISUSE_BKPT;
+  }
+  pTab = pCtx->pTab;
+  assert( (pTab->tabFlags & TF_Virtual)!=0 );
+
+  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
+  if( pParse==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    pParse->declareVtab = 1;
+    pParse->db = db;
+    pParse->nQueryLoop = 1;
+  
+    if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) 
+     && pParse->pNewTable
+     && !db->mallocFailed
+     && !pParse->pNewTable->pSelect
+     && (pParse->pNewTable->tabFlags & TF_Virtual)==0
+    ){
+      if( !pTab->aCol ){
+        pTab->aCol = pParse->pNewTable->aCol;
+        pTab->nCol = pParse->pNewTable->nCol;
+        pParse->pNewTable->nCol = 0;
+        pParse->pNewTable->aCol = 0;
+      }
+      pCtx->bDeclared = 1;
+    }else{
+      sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
+      sqlite3DbFree(db, zErr);
+      rc = SQLITE_ERROR;
+    }
+    pParse->declareVtab = 0;
+  
+    if( pParse->pVdbe ){
+      sqlite3VdbeFinalize(pParse->pVdbe);
+    }
+    sqlite3DeleteTable(db, pParse->pNewTable);
+    sqlite3ParserReset(pParse);
+    sqlite3StackFree(db, pParse);
+  }
+
+  assert( (rc&0xff)==rc );
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** This function is invoked by the vdbe to call the xDestroy method
+** of the virtual table named zTab in database iDb. This occurs
+** when a DROP TABLE is mentioned.
+**
+** This call is a no-op if zTab is not a virtual table.
+*/
+SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){
+  int rc = SQLITE_OK;
+  Table *pTab;
+
+  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
+  if( ALWAYS(pTab!=0 && pTab->pVTable!=0) ){
+    VTable *p;
+    int (*xDestroy)(sqlite3_vtab *);
+    for(p=pTab->pVTable; p; p=p->pNext){
+      assert( p->pVtab );
+      if( p->pVtab->nRef>0 ){
+        return SQLITE_LOCKED;
+      }
+    }
+    p = vtabDisconnectAll(db, pTab);
+    xDestroy = p->pMod->pModule->xDestroy;
+    assert( xDestroy!=0 );  /* Checked before the virtual table is created */
+    rc = xDestroy(p->pVtab);
+    /* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */
+    if( rc==SQLITE_OK ){
+      assert( pTab->pVTable==p && p->pNext==0 );
+      p->pVtab = 0;
+      pTab->pVTable = 0;
+      sqlite3VtabUnlock(p);
+    }
+  }
+
+  return rc;
+}
+
+/*
+** This function invokes either the xRollback or xCommit method
+** of each of the virtual tables in the sqlite3.aVTrans array. The method
+** called is identified by the second argument, "offset", which is
+** the offset of the method to call in the sqlite3_module structure.
+**
+** The array is cleared after invoking the callbacks. 
+*/
+static void callFinaliser(sqlite3 *db, int offset){
+  int i;
+  if( db->aVTrans ){
+    VTable **aVTrans = db->aVTrans;
+    db->aVTrans = 0;
+    for(i=0; i<db->nVTrans; i++){
+      VTable *pVTab = aVTrans[i];
+      sqlite3_vtab *p = pVTab->pVtab;
+      if( p ){
+        int (*x)(sqlite3_vtab *);
+        x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset);
+        if( x ) x(p);
+      }
+      pVTab->iSavepoint = 0;
+      sqlite3VtabUnlock(pVTab);
+    }
+    sqlite3DbFree(db, aVTrans);
+    db->nVTrans = 0;
+  }
+}
+
+/*
+** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans
+** array. Return the error code for the first error that occurs, or
+** SQLITE_OK if all xSync operations are successful.
+**
+** If an error message is available, leave it in p->zErrMsg.
+*/
+SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, Vdbe *p){
+  int i;
+  int rc = SQLITE_OK;
+  VTable **aVTrans = db->aVTrans;
+
+  db->aVTrans = 0;
+  for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
+    int (*x)(sqlite3_vtab *);
+    sqlite3_vtab *pVtab = aVTrans[i]->pVtab;
+    if( pVtab && (x = pVtab->pModule->xSync)!=0 ){
+      rc = x(pVtab);
+      sqlite3VtabImportErrmsg(p, pVtab);
+    }
+  }
+  db->aVTrans = aVTrans;
+  return rc;
+}
+
+/*
+** Invoke the xRollback method of all virtual tables in the 
+** sqlite3.aVTrans array. Then clear the array itself.
+*/
+SQLITE_PRIVATE int sqlite3VtabRollback(sqlite3 *db){
+  callFinaliser(db, offsetof(sqlite3_module,xRollback));
+  return SQLITE_OK;
+}
+
+/*
+** Invoke the xCommit method of all virtual tables in the 
+** sqlite3.aVTrans array. Then clear the array itself.
+*/
+SQLITE_PRIVATE int sqlite3VtabCommit(sqlite3 *db){
+  callFinaliser(db, offsetof(sqlite3_module,xCommit));
+  return SQLITE_OK;
+}
+
+/*
+** If the virtual table pVtab supports the transaction interface
+** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is
+** not currently open, invoke the xBegin method now.
+**
+** If the xBegin call is successful, place the sqlite3_vtab pointer
+** in the sqlite3.aVTrans array.
+*/
+SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){
+  int rc = SQLITE_OK;
+  const sqlite3_module *pModule;
+
+  /* Special case: If db->aVTrans is NULL and db->nVTrans is greater
+  ** than zero, then this function is being called from within a
+  ** virtual module xSync() callback. It is illegal to write to 
+  ** virtual module tables in this case, so return SQLITE_LOCKED.
+  */
+  if( sqlite3VtabInSync(db) ){
+    return SQLITE_LOCKED;
+  }
+  if( !pVTab ){
+    return SQLITE_OK;
+  } 
+  pModule = pVTab->pVtab->pModule;
+
+  if( pModule->xBegin ){
+    int i;
+
+    /* If pVtab is already in the aVTrans array, return early */
+    for(i=0; i<db->nVTrans; i++){
+      if( db->aVTrans[i]==pVTab ){
+        return SQLITE_OK;
+      }
+    }
+
+    /* Invoke the xBegin method. If successful, add the vtab to the 
+    ** sqlite3.aVTrans[] array. */
+    rc = growVTrans(db);
+    if( rc==SQLITE_OK ){
+      rc = pModule->xBegin(pVTab->pVtab);
+      if( rc==SQLITE_OK ){
+        int iSvpt = db->nStatement + db->nSavepoint;
+        addToVTrans(db, pVTab);
+        if( iSvpt ) rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN, iSvpt-1);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** Invoke either the xSavepoint, xRollbackTo or xRelease method of all
+** virtual tables that currently have an open transaction. Pass iSavepoint
+** as the second argument to the virtual table method invoked.
+**
+** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is
+** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is 
+** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with
+** an open transaction is invoked.
+**
+** If any virtual table method returns an error code other than SQLITE_OK, 
+** processing is abandoned and the error returned to the caller of this
+** function immediately. If all calls to virtual table methods are successful,
+** SQLITE_OK is returned.
+*/
+SQLITE_PRIVATE int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
+  int rc = SQLITE_OK;
+
+  assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );
+  assert( iSavepoint>=-1 );
+  if( db->aVTrans ){
+    int i;
+    for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
+      VTable *pVTab = db->aVTrans[i];
+      const sqlite3_module *pMod = pVTab->pMod->pModule;
+      if( pVTab->pVtab && pMod->iVersion>=2 ){
+        int (*xMethod)(sqlite3_vtab *, int);
+        switch( op ){
+          case SAVEPOINT_BEGIN:
+            xMethod = pMod->xSavepoint;
+            pVTab->iSavepoint = iSavepoint+1;
+            break;
+          case SAVEPOINT_ROLLBACK:
+            xMethod = pMod->xRollbackTo;
+            break;
+          default:
+            xMethod = pMod->xRelease;
+            break;
+        }
+        if( xMethod && pVTab->iSavepoint>iSavepoint ){
+          rc = xMethod(pVTab->pVtab, iSavepoint);
+        }
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** The first parameter (pDef) is a function implementation.  The
+** second parameter (pExpr) is the first argument to this function.
+** If pExpr is a column in a virtual table, then let the virtual
+** table implementation have an opportunity to overload the function.
+**
+** This routine is used to allow virtual table implementations to
+** overload MATCH, LIKE, GLOB, and REGEXP operators.
+**
+** Return either the pDef argument (indicating no change) or a 
+** new FuncDef structure that is marked as ephemeral using the
+** SQLITE_FUNC_EPHEM flag.
+*/
+SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
+  sqlite3 *db,    /* Database connection for reporting malloc problems */
+  FuncDef *pDef,  /* Function to possibly overload */
+  int nArg,       /* Number of arguments to the function */
+  Expr *pExpr     /* First argument to the function */
+){
+  Table *pTab;
+  sqlite3_vtab *pVtab;
+  sqlite3_module *pMod;
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
+  void *pArg = 0;
+  FuncDef *pNew;
+  int rc = 0;
+  char *zLowerName;
+  unsigned char *z;
+
+
+  /* Check to see the left operand is a column in a virtual table */
+  if( NEVER(pExpr==0) ) return pDef;
+  if( pExpr->op!=TK_COLUMN ) return pDef;
+  pTab = pExpr->pTab;
+  if( NEVER(pTab==0) ) return pDef;
+  if( (pTab->tabFlags & TF_Virtual)==0 ) return pDef;
+  pVtab = sqlite3GetVTable(db, pTab)->pVtab;
+  assert( pVtab!=0 );
+  assert( pVtab->pModule!=0 );
+  pMod = (sqlite3_module *)pVtab->pModule;
+  if( pMod->xFindFunction==0 ) return pDef;
+ 
+  /* Call the xFindFunction method on the virtual table implementation
+  ** to see if the implementation wants to overload this function 
+  */
+  zLowerName = sqlite3DbStrDup(db, pDef->zName);
+  if( zLowerName ){
+    for(z=(unsigned char*)zLowerName; *z; z++){
+      *z = sqlite3UpperToLower[*z];
+    }
+    rc = pMod->xFindFunction(pVtab, nArg, zLowerName, &xFunc, &pArg);
+    sqlite3DbFree(db, zLowerName);
+  }
+  if( rc==0 ){
+    return pDef;
+  }
+
+  /* Create a new ephemeral function definition for the overloaded
+  ** function */
+  pNew = sqlite3DbMallocZero(db, sizeof(*pNew)
+                             + sqlite3Strlen30(pDef->zName) + 1);
+  if( pNew==0 ){
+    return pDef;
+  }
+  *pNew = *pDef;
+  pNew->zName = (char *)&pNew[1];
+  memcpy(pNew->zName, pDef->zName, sqlite3Strlen30(pDef->zName)+1);
+  pNew->xFunc = xFunc;
+  pNew->pUserData = pArg;
+  pNew->funcFlags |= SQLITE_FUNC_EPHEM;
+  return pNew;
+}
+
+/*
+** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
+** array so that an OP_VBegin will get generated for it.  Add pTab to the
+** array if it is missing.  If pTab is already in the array, this routine
+** is a no-op.
+*/
+SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
+  Parse *pToplevel = sqlite3ParseToplevel(pParse);
+  int i, n;
+  Table **apVtabLock;
+
+  assert( IsVirtual(pTab) );
+  for(i=0; i<pToplevel->nVtabLock; i++){
+    if( pTab==pToplevel->apVtabLock[i] ) return;
+  }
+  n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
+  apVtabLock = sqlite3_realloc64(pToplevel->apVtabLock, n);
+  if( apVtabLock ){
+    pToplevel->apVtabLock = apVtabLock;
+    pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
+  }else{
+    pToplevel->db->mallocFailed = 1;
+  }
+}
+
+/*
+** Check to see if virtual tale module pMod can be have an eponymous
+** virtual table instance.  If it can, create one if one does not already
+** exist. Return non-zero if the eponymous virtual table instance exists
+** when this routine returns, and return zero if it does not exist.
+**
+** An eponymous virtual table instance is one that is named after its
+** module, and more importantly, does not require a CREATE VIRTUAL TABLE
+** statement in order to come into existance.  Eponymous virtual table
+** instances always exist.  They cannot be DROP-ed.
+**
+** Any virtual table module for which xConnect and xCreate are the same
+** method can have an eponymous virtual table instance.
+*/
+SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
+  const sqlite3_module *pModule = pMod->pModule;
+  Table *pTab;
+  char *zErr = 0;
+  int nName;
+  int rc;
+  sqlite3 *db = pParse->db;
+  if( pMod->pEpoTab ) return 1;
+  if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
+  nName = sqlite3Strlen30(pMod->zName) + 1;
+  pTab = sqlite3DbMallocZero(db, sizeof(Table) + nName);
+  if( pTab==0 ) return 0;
+  pMod->pEpoTab = pTab;
+  pTab->zName = (char*)&pTab[1];
+  memcpy(pTab->zName, pMod->zName, nName);
+  pTab->nRef = 1;
+  pTab->pSchema = db->aDb[0].pSchema;
+  pTab->tabFlags |= TF_Virtual;
+  pTab->nModuleArg = 0;
+  pTab->iPKey = -1;
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  addModuleArgument(db, pTab, 0);
+  addModuleArgument(db, pTab, sqlite3DbStrDup(db, pTab->zName));
+  rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
+  if( rc ){
+    sqlite3ErrorMsg(pParse, "%s", zErr);
+    sqlite3DbFree(db, zErr);
+    sqlite3VtabEponymousTableClear(db, pMod);
+    return 0;
+  }
+  return 1;
+}
+
+/*
+** Erase the eponymous virtual table instance associated with
+** virtual table module pMod, if it exists.
+*/
+SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){
+  Table *pTab = pMod->pEpoTab;
+  if( pTab!=0 ){
+    sqlite3DeleteColumnNames(db, pTab);
+    sqlite3VtabClear(db, pTab);
+    sqlite3DbFree(db, pTab);
+    pMod->pEpoTab = 0;
+  }
+}
+
+/*
+** Return the ON CONFLICT resolution mode in effect for the virtual
+** table update operation currently in progress.
+**
+** The results of this routine are undefined unless it is called from
+** within an xUpdate method.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *db){
+  static const unsigned char aMap[] = { 
+    SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE 
+  };
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
+  assert( OE_Ignore==4 && OE_Replace==5 );
+  assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
+  return (int)aMap[db->vtabOnConflict-1];
+}
+
+/*
+** Call from within the xCreate() or xConnect() methods to provide 
+** the SQLite core with additional information about the behavior
+** of the virtual table being implemented.
+*/
+SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3 *db, int op, ...){
+  va_list ap;
+  int rc = SQLITE_OK;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  va_start(ap, op);
+  switch( op ){
+    case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
+      VtabCtx *p = db->pVtabCtx;
+      if( !p ){
+        rc = SQLITE_MISUSE_BKPT;
+      }else{
+        assert( p->pTab==0 || (p->pTab->tabFlags & TF_Virtual)!=0 );
+        p->pVTable->bConstraint = (u8)va_arg(ap, int);
+      }
+      break;
+    }
+    default:
+      rc = SQLITE_MISUSE_BKPT;
+      break;
+  }
+  va_end(ap);
+
+  if( rc!=SQLITE_OK ) sqlite3Error(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/************** End of vtab.c ************************************************/
+/************** Begin file wherecode.c ***************************************/
+/*
+** 2015-06-06
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.
+**
+** This file was split off from where.c on 2015-06-06 in order to reduce the
+** size of where.c and make it easier to edit.  This file contains the routines
+** that actually generate the bulk of the WHERE loop code.  The original where.c
+** file retains the code that does query planning and analysis.
+*/
+/* #include "sqliteInt.h" */
+/************** Include whereInt.h in the middle of wherecode.c **************/
+/************** Begin file whereInt.h ****************************************/
+/*
+** 2013-11-12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains structure and macro definitions for the query
+** planner logic in "where.c".  These definitions are broken out into
+** a separate source file for easier editing.
+*/
+
+/*
+** Trace output macros
+*/
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+/***/ int sqlite3WhereTrace;
+#endif
+#if defined(SQLITE_DEBUG) \
+    && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
+# define WHERETRACE(K,X)  if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X
+# define WHERETRACE_ENABLED 1
+#else
+# define WHERETRACE(K,X)
+#endif
+
+/* Forward references
+*/
+typedef struct WhereClause WhereClause;
+typedef struct WhereMaskSet WhereMaskSet;
+typedef struct WhereOrInfo WhereOrInfo;
+typedef struct WhereAndInfo WhereAndInfo;
+typedef struct WhereLevel WhereLevel;
+typedef struct WhereLoop WhereLoop;
+typedef struct WherePath WherePath;
+typedef struct WhereTerm WhereTerm;
+typedef struct WhereLoopBuilder WhereLoopBuilder;
+typedef struct WhereScan WhereScan;
+typedef struct WhereOrCost WhereOrCost;
+typedef struct WhereOrSet WhereOrSet;
+
+/*
+** This object contains information needed to implement a single nested
+** loop in WHERE clause.
+**
+** Contrast this object with WhereLoop.  This object describes the
+** implementation of the loop.  WhereLoop describes the algorithm.
+** This object contains a pointer to the WhereLoop algorithm as one of
+** its elements.
+**
+** The WhereInfo object contains a single instance of this object for
+** each term in the FROM clause (which is to say, for each of the
+** nested loops as implemented).  The order of WhereLevel objects determines
+** the loop nested order, with WhereInfo.a[0] being the outer loop and
+** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
+*/
+struct WhereLevel {
+  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
+  int iTabCur;          /* The VDBE cursor used to access the table */
+  int iIdxCur;          /* The VDBE cursor used to access pIdx */
+  int addrBrk;          /* Jump here to break out of the loop */
+  int addrNxt;          /* Jump here to start the next IN combination */
+  int addrSkip;         /* Jump here for next iteration of skip-scan */
+  int addrCont;         /* Jump here to continue with the next loop cycle */
+  int addrFirst;        /* First instruction of interior of the loop */
+  int addrBody;         /* Beginning of the body of this loop */
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+  int iLikeRepCntr;     /* LIKE range processing counter register */
+  int addrLikeRep;      /* LIKE range processing address */
+#endif
+  u8 iFrom;             /* Which entry in the FROM clause */
+  u8 op, p3, p5;        /* Opcode, P3 & P5 of the opcode that ends the loop */
+  int p1, p2;           /* Operands of the opcode used to ends the loop */
+  union {               /* Information that depends on pWLoop->wsFlags */
+    struct {
+      int nIn;              /* Number of entries in aInLoop[] */
+      struct InLoop {
+        int iCur;              /* The VDBE cursor used by this IN operator */
+        int addrInTop;         /* Top of the IN loop */
+        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
+      } *aInLoop;           /* Information about each nested IN operator */
+    } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
+    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
+  } u;
+  struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
+  Bitmask notReady;          /* FROM entries not usable at this level */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  int addrVisit;        /* Address at which row is visited */
+#endif
+};
+
+/*
+** Each instance of this object represents an algorithm for evaluating one
+** term of a join.  Every term of the FROM clause will have at least
+** one corresponding WhereLoop object (unless INDEXED BY constraints
+** prevent a query solution - which is an error) and many terms of the
+** FROM clause will have multiple WhereLoop objects, each describing a
+** potential way of implementing that FROM-clause term, together with
+** dependencies and cost estimates for using the chosen algorithm.
+**
+** Query planning consists of building up a collection of these WhereLoop
+** objects, then computing a particular sequence of WhereLoop objects, with
+** one WhereLoop object per FROM clause term, that satisfy all dependencies
+** and that minimize the overall cost.
+*/
+struct WhereLoop {
+  Bitmask prereq;       /* Bitmask of other loops that must run first */
+  Bitmask maskSelf;     /* Bitmask identifying table iTab */
+#ifdef SQLITE_DEBUG
+  char cId;             /* Symbolic ID of this loop for debugging use */
+#endif
+  u8 iTab;              /* Position in FROM clause of table for this loop */
+  u8 iSortIdx;          /* Sorting index number.  0==None */
+  LogEst rSetup;        /* One-time setup cost (ex: create transient index) */
+  LogEst rRun;          /* Cost of running each loop */
+  LogEst nOut;          /* Estimated number of output rows */
+  union {
+    struct {               /* Information for internal btree tables */
+      u16 nEq;               /* Number of equality constraints */
+      Index *pIndex;         /* Index used, or NULL */
+    } btree;
+    struct {               /* Information for virtual tables */
+      int idxNum;            /* Index number */
+      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
+      i8 isOrdered;          /* True if satisfies ORDER BY */
+      u16 omitMask;          /* Terms that may be omitted */
+      char *idxStr;          /* Index identifier string */
+    } vtab;
+  } u;
+  u32 wsFlags;          /* WHERE_* flags describing the plan */
+  u16 nLTerm;           /* Number of entries in aLTerm[] */
+  u16 nSkip;            /* Number of NULL aLTerm[] entries */
+  /**** whereLoopXfer() copies fields above ***********************/
+# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
+  u16 nLSlot;           /* Number of slots allocated for aLTerm[] */
+  WhereTerm **aLTerm;   /* WhereTerms used */
+  WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
+  WhereTerm *aLTermSpace[3];  /* Initial aLTerm[] space */
+};
+
+/* This object holds the prerequisites and the cost of running a
+** subquery on one operand of an OR operator in the WHERE clause.
+** See WhereOrSet for additional information 
+*/
+struct WhereOrCost {
+  Bitmask prereq;     /* Prerequisites */
+  LogEst rRun;        /* Cost of running this subquery */
+  LogEst nOut;        /* Number of outputs for this subquery */
+};
+
+/* The WhereOrSet object holds a set of possible WhereOrCosts that
+** correspond to the subquery(s) of OR-clause processing.  Only the
+** best N_OR_COST elements are retained.
+*/
+#define N_OR_COST 3
+struct WhereOrSet {
+  u16 n;                      /* Number of valid a[] entries */
+  WhereOrCost a[N_OR_COST];   /* Set of best costs */
+};
+
+/*
+** Each instance of this object holds a sequence of WhereLoop objects
+** that implement some or all of a query plan.
+**
+** Think of each WhereLoop object as a node in a graph with arcs
+** showing dependencies and costs for travelling between nodes.  (That is
+** not a completely accurate description because WhereLoop costs are a
+** vector, not a scalar, and because dependencies are many-to-one, not
+** one-to-one as are graph nodes.  But it is a useful visualization aid.)
+** Then a WherePath object is a path through the graph that visits some
+** or all of the WhereLoop objects once.
+**
+** The "solver" works by creating the N best WherePath objects of length
+** 1.  Then using those as a basis to compute the N best WherePath objects
+** of length 2.  And so forth until the length of WherePaths equals the
+** number of nodes in the FROM clause.  The best (lowest cost) WherePath
+** at the end is the chosen query plan.
+*/
+struct WherePath {
+  Bitmask maskLoop;     /* Bitmask of all WhereLoop objects in this path */
+  Bitmask revLoop;      /* aLoop[]s that should be reversed for ORDER BY */
+  LogEst nRow;          /* Estimated number of rows generated by this path */
+  LogEst rCost;         /* Total cost of this path */
+  LogEst rUnsorted;     /* Total cost of this path ignoring sorting costs */
+  i8 isOrdered;         /* No. of ORDER BY terms satisfied. -1 for unknown */
+  WhereLoop **aLoop;    /* Array of WhereLoop objects implementing this path */
+};
+
+/*
+** The query generator uses an array of instances of this structure to
+** help it analyze the subexpressions of the WHERE clause.  Each WHERE
+** clause subexpression is separated from the others by AND operators,
+** usually, or sometimes subexpressions separated by OR.
+**
+** All WhereTerms are collected into a single WhereClause structure.  
+** The following identity holds:
+**
+**        WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm
+**
+** When a term is of the form:
+**
+**              X <op> <expr>
+**
+** where X is a column name and <op> is one of certain operators,
+** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the
+** cursor number and column number for X.  WhereTerm.eOperator records
+** the <op> using a bitmask encoding defined by WO_xxx below.  The
+** use of a bitmask encoding for the operator allows us to search
+** quickly for terms that match any of several different operators.
+**
+** A WhereTerm might also be two or more subterms connected by OR:
+**
+**         (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
+**
+** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
+** and the WhereTerm.u.pOrInfo field points to auxiliary information that
+** is collected about the OR clause.
+**
+** If a term in the WHERE clause does not match either of the two previous
+** categories, then eOperator==0.  The WhereTerm.pExpr field is still set
+** to the original subexpression content and wtFlags is set up appropriately
+** but no other fields in the WhereTerm object are meaningful.
+**
+** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,
+** but they do so indirectly.  A single WhereMaskSet structure translates
+** cursor number into bits and the translated bit is stored in the prereq
+** fields.  The translation is used in order to maximize the number of
+** bits that will fit in a Bitmask.  The VDBE cursor numbers might be
+** spread out over the non-negative integers.  For example, the cursor
+** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45.  The WhereMaskSet
+** translates these sparse cursor numbers into consecutive integers
+** beginning with 0 in order to make the best possible use of the available
+** bits in the Bitmask.  So, in the example above, the cursor numbers
+** would be mapped into integers 0 through 7.
+**
+** The number of terms in a join is limited by the number of bits
+** in prereqRight and prereqAll.  The default is 64 bits, hence SQLite
+** is only able to process joins with 64 or fewer tables.
+*/
+struct WhereTerm {
+  Expr *pExpr;            /* Pointer to the subexpression that is this term */
+  int iParent;            /* Disable pWC->a[iParent] when this term disabled */
+  int leftCursor;         /* Cursor number of X in "X <op> <expr>" */
+  union {
+    int leftColumn;         /* Column number of X in "X <op> <expr>" */
+    WhereOrInfo *pOrInfo;   /* Extra information if (eOperator & WO_OR)!=0 */
+    WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
+  } u;
+  LogEst truthProb;       /* Probability of truth for this expression */
+  u16 eOperator;          /* A WO_xx value describing <op> */
+  u16 wtFlags;            /* TERM_xxx bit flags.  See below */
+  u8 nChild;              /* Number of children that must disable us */
+  u8 eMatchOp;            /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
+  WhereClause *pWC;       /* The clause this term is part of */
+  Bitmask prereqRight;    /* Bitmask of tables used by pExpr->pRight */
+  Bitmask prereqAll;      /* Bitmask of tables referenced by pExpr */
+};
+
+/*
+** Allowed values of WhereTerm.wtFlags
+*/
+#define TERM_DYNAMIC    0x01   /* Need to call sqlite3ExprDelete(db, pExpr) */
+#define TERM_VIRTUAL    0x02   /* Added by the optimizer.  Do not code */
+#define TERM_CODED      0x04   /* This term is already coded */
+#define TERM_COPIED     0x08   /* Has a child */
+#define TERM_ORINFO     0x10   /* Need to free the WhereTerm.u.pOrInfo object */
+#define TERM_ANDINFO    0x20   /* Need to free the WhereTerm.u.pAndInfo obj */
+#define TERM_OR_OK      0x40   /* Used during OR-clause processing */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+#  define TERM_VNULL    0x80   /* Manufactured x>NULL or x<=NULL term */
+#else
+#  define TERM_VNULL    0x00   /* Disabled if not using stat3 */
+#endif
+#define TERM_LIKEOPT    0x100  /* Virtual terms from the LIKE optimization */
+#define TERM_LIKECOND   0x200  /* Conditionally this LIKE operator term */
+#define TERM_LIKE       0x400  /* The original LIKE operator */
+#define TERM_IS         0x800  /* Term.pExpr is an IS operator */
+
+/*
+** An instance of the WhereScan object is used as an iterator for locating
+** terms in the WHERE clause that are useful to the query planner.
+*/
+struct WhereScan {
+  WhereClause *pOrigWC;      /* Original, innermost WhereClause */
+  WhereClause *pWC;          /* WhereClause currently being scanned */
+  const char *zCollName;     /* Required collating sequence, if not NULL */
+  Expr *pIdxExpr;            /* Search for this index expression */
+  char idxaff;               /* Must match this affinity, if zCollName!=NULL */
+  unsigned char nEquiv;      /* Number of entries in aEquiv[] */
+  unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
+  u32 opMask;                /* Acceptable operators */
+  int k;                     /* Resume scanning at this->pWC->a[this->k] */
+  int aiCur[11];             /* Cursors in the equivalence class */
+  i16 aiColumn[11];          /* Corresponding column number in the eq-class */
+};
+
+/*
+** An instance of the following structure holds all information about a
+** WHERE clause.  Mostly this is a container for one or more WhereTerms.
+**
+** Explanation of pOuter:  For a WHERE clause of the form
+**
+**           a AND ((b AND c) OR (d AND e)) AND f
+**
+** There are separate WhereClause objects for the whole clause and for
+** the subclauses "(b AND c)" and "(d AND e)".  The pOuter field of the
+** subclauses points to the WhereClause object for the whole clause.
+*/
+struct WhereClause {
+  WhereInfo *pWInfo;       /* WHERE clause processing context */
+  WhereClause *pOuter;     /* Outer conjunction */
+  u8 op;                   /* Split operator.  TK_AND or TK_OR */
+  int nTerm;               /* Number of terms */
+  int nSlot;               /* Number of entries in a[] */
+  WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
+#if defined(SQLITE_SMALL_STACK)
+  WhereTerm aStatic[1];    /* Initial static space for a[] */
+#else
+  WhereTerm aStatic[8];    /* Initial static space for a[] */
+#endif
+};
+
+/*
+** A WhereTerm with eOperator==WO_OR has its u.pOrInfo pointer set to
+** a dynamically allocated instance of the following structure.
+*/
+struct WhereOrInfo {
+  WhereClause wc;          /* Decomposition into subterms */
+  Bitmask indexable;       /* Bitmask of all indexable tables in the clause */
+};
+
+/*
+** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to
+** a dynamically allocated instance of the following structure.
+*/
+struct WhereAndInfo {
+  WhereClause wc;          /* The subexpression broken out */
+};
+
+/*
+** An instance of the following structure keeps track of a mapping
+** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.
+**
+** The VDBE cursor numbers are small integers contained in 
+** SrcList_item.iCursor and Expr.iTable fields.  For any given WHERE 
+** clause, the cursor numbers might not begin with 0 and they might
+** contain gaps in the numbering sequence.  But we want to make maximum
+** use of the bits in our bitmasks.  This structure provides a mapping
+** from the sparse cursor numbers into consecutive integers beginning
+** with 0.
+**
+** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
+** corresponds VDBE cursor number B.  The A-th bit of a bitmask is 1<<A.
+**
+** For example, if the WHERE clause expression used these VDBE
+** cursors:  4, 5, 8, 29, 57, 73.  Then the  WhereMaskSet structure
+** would map those cursor numbers into bits 0 through 5.
+**
+** Note that the mapping is not necessarily ordered.  In the example
+** above, the mapping might go like this:  4->3, 5->1, 8->2, 29->0,
+** 57->5, 73->4.  Or one of 719 other combinations might be used. It
+** does not really matter.  What is important is that sparse cursor
+** numbers all get mapped into bit numbers that begin with 0 and contain
+** no gaps.
+*/
+struct WhereMaskSet {
+  int n;                        /* Number of assigned cursor values */
+  int ix[BMS];                  /* Cursor assigned to each bit */
+};
+
+/*
+** Initialize a WhereMaskSet object
+*/
+#define initMaskSet(P)  (P)->n=0
+
+/*
+** This object is a convenience wrapper holding all information needed
+** to construct WhereLoop objects for a particular query.
+*/
+struct WhereLoopBuilder {
+  WhereInfo *pWInfo;        /* Information about this WHERE */
+  WhereClause *pWC;         /* WHERE clause terms */
+  ExprList *pOrderBy;       /* ORDER BY clause */
+  WhereLoop *pNew;          /* Template WhereLoop */
+  WhereOrSet *pOrSet;       /* Record best loops here, if not NULL */
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  UnpackedRecord *pRec;     /* Probe for stat4 (if required) */
+  int nRecValid;            /* Number of valid fields currently in pRec */
+#endif
+};
+
+/*
+** The WHERE clause processing routine has two halves.  The
+** first part does the start of the WHERE loop and the second
+** half does the tail of the WHERE loop.  An instance of
+** this structure is returned by the first half and passed
+** into the second half to give some continuity.
+**
+** An instance of this object holds the complete state of the query
+** planner.
+*/
+struct WhereInfo {
+  Parse *pParse;            /* Parsing and code generating context */
+  SrcList *pTabList;        /* List of tables in the join */
+  ExprList *pOrderBy;       /* The ORDER BY clause or NULL */
+  ExprList *pResultSet;     /* Result set. DISTINCT operates on these */
+  WhereLoop *pLoops;        /* List of all WhereLoop objects */
+  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
+  LogEst nRowOut;           /* Estimated number of output rows */
+  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
+  i8 nOBSat;                /* Number of ORDER BY terms satisfied by indices */
+  u8 sorted;                /* True if really sorted (not just grouped) */
+  u8 eOnePass;              /* ONEPASS_OFF, or _SINGLE, or _MULTI */
+  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
+  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
+  u8 nLevel;                /* Number of nested loop */
+  int iTop;                 /* The very beginning of the WHERE loop */
+  int iContinue;            /* Jump here to continue with next record */
+  int iBreak;               /* Jump here to break out of the loop */
+  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
+  int aiCurOnePass[2];      /* OP_OpenWrite cursors for the ONEPASS opt */
+  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
+  WhereClause sWC;          /* Decomposition of the WHERE clause */
+  WhereLevel a[1];          /* Information about each nest loop in WHERE */
+};
+
+/*
+** Private interfaces - callable only by other where.c routines.
+**
+** where.c:
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+);
+
+/* wherecode.c: */
+#ifndef SQLITE_OMIT_EXPLAIN
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+);
+#else
+# define sqlite3WhereExplainOneScan(u,v,w,x,y,z) 0
+#endif /* SQLITE_OMIT_EXPLAIN */
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
+);
+#else
+# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
+#endif
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
+);
+
+/* whereexpr.c: */
+SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);
+
+
+
+
+
+/*
+** Bitmasks for the operators on WhereTerm objects.  These are all
+** operators that are of interest to the query planner.  An
+** OR-ed combination of these values can be used when searching for
+** particular WhereTerms within a WhereClause.
+*/
+#define WO_IN     0x0001
+#define WO_EQ     0x0002
+#define WO_LT     (WO_EQ<<(TK_LT-TK_EQ))
+#define WO_LE     (WO_EQ<<(TK_LE-TK_EQ))
+#define WO_GT     (WO_EQ<<(TK_GT-TK_EQ))
+#define WO_GE     (WO_EQ<<(TK_GE-TK_EQ))
+#define WO_MATCH  0x0040
+#define WO_IS     0x0080
+#define WO_ISNULL 0x0100
+#define WO_OR     0x0200       /* Two or more OR-connected terms */
+#define WO_AND    0x0400       /* Two or more AND-connected terms */
+#define WO_EQUIV  0x0800       /* Of the form A==B, both columns */
+#define WO_NOOP   0x1000       /* This term does not restrict search space */
+
+#define WO_ALL    0x1fff       /* Mask of all possible WO_* values */
+#define WO_SINGLE 0x01ff       /* Mask of all non-compound WO_* values */
+
+/*
+** These are definitions of bits in the WhereLoop.wsFlags field.
+** The particular combination of bits in each WhereLoop help to
+** determine the algorithm that WhereLoop represents.
+*/
+#define WHERE_COLUMN_EQ    0x00000001  /* x=EXPR */
+#define WHERE_COLUMN_RANGE 0x00000002  /* x<EXPR and/or x>EXPR */
+#define WHERE_COLUMN_IN    0x00000004  /* x IN (...) */
+#define WHERE_COLUMN_NULL  0x00000008  /* x IS NULL */
+#define WHERE_CONSTRAINT   0x0000000f  /* Any of the WHERE_COLUMN_xxx values */
+#define WHERE_TOP_LIMIT    0x00000010  /* x<EXPR or x<=EXPR constraint */
+#define WHERE_BTM_LIMIT    0x00000020  /* x>EXPR or x>=EXPR constraint */
+#define WHERE_BOTH_LIMIT   0x00000030  /* Both x>EXPR and x<EXPR */
+#define WHERE_IDX_ONLY     0x00000040  /* Use index only - omit table */
+#define WHERE_IPK          0x00000100  /* x is the INTEGER PRIMARY KEY */
+#define WHERE_INDEXED      0x00000200  /* WhereLoop.u.btree.pIndex is valid */
+#define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */
+#define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */
+#define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
+#define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
+#define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
+#define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */
+#define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/
+#define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */
+
+/************** End of whereInt.h ********************************************/
+/************** Continuing where we left off in wherecode.c ******************/
+
+#ifndef SQLITE_OMIT_EXPLAIN
+/*
+** This routine is a helper for explainIndexRange() below
+**
+** pStr holds the text of an expression that we are building up one term
+** at a time.  This routine adds a new term to the end of the expression.
+** Terms are separated by AND so add the "AND" text for second and subsequent
+** terms only.
+*/
+static void explainAppendTerm(
+  StrAccum *pStr,             /* The text expression being built */
+  int iTerm,                  /* Index of this term.  First is zero */
+  const char *zColumn,        /* Name of the column */
+  const char *zOp             /* Name of the operator */
+){
+  if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+  sqlite3StrAccumAppendAll(pStr, zColumn);
+  sqlite3StrAccumAppend(pStr, zOp, 1);
+  sqlite3StrAccumAppend(pStr, "?", 1);
+}
+
+/*
+** Return the name of the i-th column of the pIdx index.
+*/
+static const char *explainIndexColumnName(Index *pIdx, int i){
+  i = pIdx->aiColumn[i];
+  if( i==XN_EXPR ) return "<expr>";
+  if( i==XN_ROWID ) return "rowid";
+  return pIdx->pTable->aCol[i].zName;
+}
+
+/*
+** Argument pLevel describes a strategy for scanning table pTab. This 
+** function appends text to pStr that describes the subset of table
+** rows scanned by the strategy in the form of an SQL expression.
+**
+** For example, if the query:
+**
+**   SELECT * FROM t1 WHERE a=1 AND b>2;
+**
+** is run and there is an index on (a, b), then this function returns a
+** string similar to:
+**
+**   "a=? AND b>?"
+*/
+static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){
+  Index *pIndex = pLoop->u.btree.pIndex;
+  u16 nEq = pLoop->u.btree.nEq;
+  u16 nSkip = pLoop->nSkip;
+  int i, j;
+
+  if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
+  sqlite3StrAccumAppend(pStr, " (", 2);
+  for(i=0; i<nEq; i++){
+    const char *z = explainIndexColumnName(pIndex, i);
+    if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
+    sqlite3XPrintf(pStr, 0, i>=nSkip ? "%s=?" : "ANY(%s)", z);
+  }
+
+  j = i;
+  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
+    const char *z = explainIndexColumnName(pIndex, i);
+    explainAppendTerm(pStr, i++, z, ">");
+  }
+  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
+    const char *z = explainIndexColumnName(pIndex, j);
+    explainAppendTerm(pStr, i, z, "<");
+  }
+  sqlite3StrAccumAppend(pStr, ")", 1);
+}
+
+/*
+** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
+** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
+** defined at compile-time. If it is not a no-op, a single OP_Explain opcode 
+** is added to the output to describe the table scan strategy in pLevel.
+**
+** If an OP_Explain opcode is added to the VM, its address is returned.
+** Otherwise, if no OP_Explain is coded, zero is returned.
+*/
+SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
+  Parse *pParse,                  /* Parse context */
+  SrcList *pTabList,              /* Table list this loop refers to */
+  WhereLevel *pLevel,             /* Scan to write OP_Explain opcode for */
+  int iLevel,                     /* Value for "level" column of output */
+  int iFrom,                      /* Value for "from" column of output */
+  u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
+){
+  int ret = 0;
+#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
+  if( pParse->explain==2 )
+#endif
+  {
+    struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
+    Vdbe *v = pParse->pVdbe;      /* VM being constructed */
+    sqlite3 *db = pParse->db;     /* Database handle */
+    int iId = pParse->iSelectId;  /* Select id (left-most output column) */
+    int isSearch;                 /* True for a SEARCH. False for SCAN. */
+    WhereLoop *pLoop;             /* The controlling WhereLoop object */
+    u32 flags;                    /* Flags that describe this loop */
+    char *zMsg;                   /* Text to add to EQP output */
+    StrAccum str;                 /* EQP output string */
+    char zBuf[100];               /* Initial space for EQP output string */
+
+    pLoop = pLevel->pWLoop;
+    flags = pLoop->wsFlags;
+    if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return 0;
+
+    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+
+    sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
+    sqlite3StrAccumAppendAll(&str, isSearch ? "SEARCH" : "SCAN");
+    if( pItem->pSelect ){
+      sqlite3XPrintf(&str, 0, " SUBQUERY %d", pItem->iSelectId);
+    }else{
+      sqlite3XPrintf(&str, 0, " TABLE %s", pItem->zName);
+    }
+
+    if( pItem->zAlias ){
+      sqlite3XPrintf(&str, 0, " AS %s", pItem->zAlias);
+    }
+    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
+      const char *zFmt = 0;
+      Index *pIdx;
+
+      assert( pLoop->u.btree.pIndex!=0 );
+      pIdx = pLoop->u.btree.pIndex;
+      assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
+      if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
+        if( isSearch ){
+          zFmt = "PRIMARY KEY";
+        }
+      }else if( flags & WHERE_PARTIALIDX ){
+        zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
+      }else if( flags & WHERE_AUTO_INDEX ){
+        zFmt = "AUTOMATIC COVERING INDEX";
+      }else if( flags & WHERE_IDX_ONLY ){
+        zFmt = "COVERING INDEX %s";
+      }else{
+        zFmt = "INDEX %s";
+      }
+      if( zFmt ){
+        sqlite3StrAccumAppend(&str, " USING ", 7);
+        sqlite3XPrintf(&str, 0, zFmt, pIdx->zName);
+        explainIndexRange(&str, pLoop);
+      }
+    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
+      const char *zRangeOp;
+      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
+        zRangeOp = "=";
+      }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
+        zRangeOp = ">? AND rowid<";
+      }else if( flags&WHERE_BTM_LIMIT ){
+        zRangeOp = ">";
+      }else{
+        assert( flags&WHERE_TOP_LIMIT);
+        zRangeOp = "<";
+      }
+      sqlite3XPrintf(&str, 0, " USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
+    }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
+      sqlite3XPrintf(&str, 0, " VIRTUAL TABLE INDEX %d:%s",
+                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
+    }
+#endif
+#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
+    if( pLoop->nOut>=10 ){
+      sqlite3XPrintf(&str, 0, " (~%llu rows)", sqlite3LogEstToInt(pLoop->nOut));
+    }else{
+      sqlite3StrAccumAppend(&str, " (~1 row)", 9);
+    }
+#endif
+    zMsg = sqlite3StrAccumFinish(&str);
+    ret = sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg,P4_DYNAMIC);
+  }
+  return ret;
+}
+#endif /* SQLITE_OMIT_EXPLAIN */
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+/*
+** Configure the VM passed as the first argument with an
+** sqlite3_stmt_scanstatus() entry corresponding to the scan used to 
+** implement level pLvl. Argument pSrclist is a pointer to the FROM 
+** clause that the scan reads data from.
+**
+** If argument addrExplain is not 0, it must be the address of an 
+** OP_Explain instruction that describes the same loop.
+*/
+SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
+  Vdbe *v,                        /* Vdbe to add scanstatus entry to */
+  SrcList *pSrclist,              /* FROM clause pLvl reads data from */
+  WhereLevel *pLvl,               /* Level to add scanstatus() entry for */
+  int addrExplain                 /* Address of OP_Explain (or 0) */
+){
+  const char *zObj = 0;
+  WhereLoop *pLoop = pLvl->pWLoop;
+  if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0  &&  pLoop->u.btree.pIndex!=0 ){
+    zObj = pLoop->u.btree.pIndex->zName;
+  }else{
+    zObj = pSrclist->a[pLvl->iFrom].zName;
+  }
+  sqlite3VdbeScanStatus(
+      v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
+  );
+}
+#endif
+
+
+/*
+** Disable a term in the WHERE clause.  Except, do not disable the term
+** if it controls a LEFT OUTER JOIN and it did not originate in the ON
+** or USING clause of that join.
+**
+** Consider the term t2.z='ok' in the following queries:
+**
+**   (1)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
+**   (2)  SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
+**   (3)  SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
+**
+** The t2.z='ok' is disabled in the in (2) because it originates
+** in the ON clause.  The term is disabled in (3) because it is not part
+** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
+**
+** Disabling a term causes that term to not be tested in the inner loop
+** of the join.  Disabling is an optimization.  When terms are satisfied
+** by indices, we disable them to prevent redundant tests in the inner
+** loop.  We would get the correct results if nothing were ever disabled,
+** but joins might run a little slower.  The trick is to disable as much
+** as we can without disabling too much.  If we disabled in (1), we'd get
+** the wrong answer.  See ticket #813.
+**
+** If all the children of a term are disabled, then that term is also
+** automatically disabled.  In this way, terms get disabled if derived
+** virtual terms are tested first.  For example:
+**
+**      x GLOB 'abc*' AND x>='abc' AND x<'acd'
+**      \___________/     \______/     \_____/
+**         parent          child1       child2
+**
+** Only the parent term was in the original WHERE clause.  The child1
+** and child2 terms were added by the LIKE optimization.  If both of
+** the virtual child terms are valid, then testing of the parent can be 
+** skipped.
+**
+** Usually the parent term is marked as TERM_CODED.  But if the parent
+** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
+** The TERM_LIKECOND marking indicates that the term should be coded inside
+** a conditional such that is only evaluated on the second pass of a
+** LIKE-optimization loop, when scanning BLOBs instead of strings.
+*/
+static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
+  int nLoop = 0;
+  while( pTerm
+      && (pTerm->wtFlags & TERM_CODED)==0
+      && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+      && (pLevel->notReady & pTerm->prereqAll)==0
+  ){
+    if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
+      pTerm->wtFlags |= TERM_LIKECOND;
+    }else{
+      pTerm->wtFlags |= TERM_CODED;
+    }
+    if( pTerm->iParent<0 ) break;
+    pTerm = &pTerm->pWC->a[pTerm->iParent];
+    pTerm->nChild--;
+    if( pTerm->nChild!=0 ) break;
+    nLoop++;
+  }
+}
+
+/*
+** Code an OP_Affinity opcode to apply the column affinity string zAff
+** to the n registers starting at base. 
+**
+** As an optimization, SQLITE_AFF_BLOB entries (which are no-ops) at the
+** beginning and end of zAff are ignored.  If all entries in zAff are
+** SQLITE_AFF_BLOB, then no code gets generated.
+**
+** This routine makes its own copy of zAff so that the caller is free
+** to modify zAff after this routine returns.
+*/
+static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
+  Vdbe *v = pParse->pVdbe;
+  if( zAff==0 ){
+    assert( pParse->db->mallocFailed );
+    return;
+  }
+  assert( v!=0 );
+
+  /* Adjust base and n to skip over SQLITE_AFF_BLOB entries at the beginning
+  ** and end of the affinity string.
+  */
+  while( n>0 && zAff[0]==SQLITE_AFF_BLOB ){
+    n--;
+    base++;
+    zAff++;
+  }
+  while( n>1 && zAff[n-1]==SQLITE_AFF_BLOB ){
+    n--;
+  }
+
+  /* Code the OP_Affinity opcode if there is anything left to do. */
+  if( n>0 ){
+    sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
+    sqlite3VdbeChangeP4(v, -1, zAff, n);
+    sqlite3ExprCacheAffinityChange(pParse, base, n);
+  }
+}
+
+
+/*
+** Generate code for a single equality term of the WHERE clause.  An equality
+** term can be either X=expr or X IN (...).   pTerm is the term to be 
+** coded.
+**
+** The current value for the constraint is left in register iReg.
+**
+** For a constraint of the form X=expr, the expression is evaluated and its
+** result is left on the stack.  For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
+*/
+static int codeEqualityTerm(
+  Parse *pParse,      /* The parsing context */
+  WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
+  WhereLevel *pLevel, /* The level of the FROM clause we are working on */
+  int iEq,            /* Index of the equality term within this level */
+  int bRev,           /* True for reverse-order IN operations */
+  int iTarget         /* Attempt to leave results in this register */
+){
+  Expr *pX = pTerm->pExpr;
+  Vdbe *v = pParse->pVdbe;
+  int iReg;                  /* Register holding results */
+
+  assert( iTarget>0 );
+  if( pX->op==TK_EQ || pX->op==TK_IS ){
+    iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+  }else if( pX->op==TK_ISNULL ){
+    iReg = iTarget;
+    sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
+  }else{
+    int eType;
+    int iTab;
+    struct InLoop *pIn;
+    WhereLoop *pLoop = pLevel->pWLoop;
+
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+      && pLoop->u.btree.pIndex!=0
+      && pLoop->u.btree.pIndex->aSortOrder[iEq]
+    ){
+      testcase( iEq==0 );
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    assert( pX->op==TK_IN );
+    iReg = iTarget;
+    eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0);
+    if( eType==IN_INDEX_INDEX_DESC ){
+      testcase( bRev );
+      bRev = !bRev;
+    }
+    iTab = pX->iTable;
+    sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
+    VdbeCoverageIf(v, bRev);
+    VdbeCoverageIf(v, !bRev);
+    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+    pLoop->wsFlags |= WHERE_IN_ABLE;
+    if( pLevel->u.in.nIn==0 ){
+      pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+    }
+    pLevel->u.in.nIn++;
+    pLevel->u.in.aInLoop =
+       sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
+                              sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
+    pIn = pLevel->u.in.aInLoop;
+    if( pIn ){
+      pIn += pLevel->u.in.nIn - 1;
+      pIn->iCur = iTab;
+      if( eType==IN_INDEX_ROWID ){
+        pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iReg);
+      }else{
+        pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg);
+      }
+      pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
+      sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v);
+    }else{
+      pLevel->u.in.nIn = 0;
+    }
+#endif
+  }
+  disableTerm(pLevel, pTerm);
+  return iReg;
+}
+
+/*
+** Generate code that will evaluate all == and IN constraints for an
+** index scan.
+**
+** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
+** Suppose the WHERE clause is this:  a==5 AND b IN (1,2,3) AND c>5 AND c<10
+** The index has as many as three equality constraints, but in this
+** example, the third "c" value is an inequality.  So only two 
+** constraints are coded.  This routine will generate code to evaluate
+** a==5 and b IN (1,2,3).  The current values for a and b will be stored
+** in consecutive registers and the index of the first register is returned.
+**
+** In the example above nEq==2.  But this subroutine works for any value
+** of nEq including 0.  If nEq==0, this routine is nearly a no-op.
+** The only thing it does is allocate the pLevel->iMem memory cell and
+** compute the affinity string.
+**
+** The nExtraReg parameter is 0 or 1.  It is 0 if all WHERE clause constraints
+** are == or IN and are covered by the nEq.  nExtraReg is 1 if there is
+** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
+** occurs after the nEq quality constraints.
+**
+** This routine allocates a range of nEq+nExtraReg memory cells and returns
+** the index of the first memory cell in that range. The code that
+** calls this routine will use that memory range to store keys for
+** start and termination conditions of the loop.
+** key value of the loop.  If one or more IN operators appear, then
+** this routine allocates an additional nEq memory cells for internal
+** use.
+**
+** Before returning, *pzAff is set to point to a buffer containing a
+** copy of the column affinity string of the index allocated using
+** sqlite3DbMalloc(). Except, entries in the copy of the string associated
+** with equality constraints that use BLOB or NONE affinity are set to
+** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
+**
+**   CREATE TABLE t1(a TEXT PRIMARY KEY, b);
+**   SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
+**
+** In the example above, the index on t1(a) has TEXT affinity. But since
+** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
+** no conversion should be attempted before using a t2.b value as part of
+** a key to search the index. Hence the first byte in the returned affinity
+** string in this example would be set to SQLITE_AFF_BLOB.
+*/
+static int codeAllEqualityTerms(
+  Parse *pParse,        /* Parsing context */
+  WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
+  int bRev,             /* Reverse the order of IN operators */
+  int nExtraReg,        /* Number of extra registers to allocate */
+  char **pzAff          /* OUT: Set to point to affinity string */
+){
+  u16 nEq;                      /* The number of == or IN constraints to code */
+  u16 nSkip;                    /* Number of left-most columns to skip */
+  Vdbe *v = pParse->pVdbe;      /* The vm under construction */
+  Index *pIdx;                  /* The index being used for this loop */
+  WhereTerm *pTerm;             /* A single constraint term */
+  WhereLoop *pLoop;             /* The WhereLoop object */
+  int j;                        /* Loop counter */
+  int regBase;                  /* Base register */
+  int nReg;                     /* Number of registers to allocate */
+  char *zAff;                   /* Affinity string to return */
+
+  /* This module is only called on query plans that use an index. */
+  pLoop = pLevel->pWLoop;
+  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  nEq = pLoop->u.btree.nEq;
+  nSkip = pLoop->nSkip;
+  pIdx = pLoop->u.btree.pIndex;
+  assert( pIdx!=0 );
+
+  /* Figure out how many memory cells we will need then allocate them.
+  */
+  regBase = pParse->nMem + 1;
+  nReg = pLoop->u.btree.nEq + nExtraReg;
+  pParse->nMem += nReg;
+
+  zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
+  if( !zAff ){
+    pParse->db->mallocFailed = 1;
+  }
+
+  if( nSkip ){
+    int iIdxCur = pLevel->iIdxCur;
+    sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
+    j = sqlite3VdbeAddOp0(v, OP_Goto);
+    pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
+                            iIdxCur, 0, regBase, nSkip);
+    VdbeCoverageIf(v, bRev==0);
+    VdbeCoverageIf(v, bRev!=0);
+    sqlite3VdbeJumpHere(v, j);
+    for(j=0; j<nSkip; j++){
+      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
+      testcase( pIdx->aiColumn[j]==XN_EXPR );
+      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
+    }
+  }    
+
+  /* Evaluate the equality constraints
+  */
+  assert( zAff==0 || (int)strlen(zAff)>=nEq );
+  for(j=nSkip; j<nEq; j++){
+    int r1;
+    pTerm = pLoop->aLTerm[j];
+    assert( pTerm!=0 );
+    /* The following testcase is true for indices with redundant columns. 
+    ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
+    testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
+    if( r1!=regBase+j ){
+      if( nReg==1 ){
+        sqlite3ReleaseTempReg(pParse, regBase);
+        regBase = r1;
+      }else{
+        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
+      }
+    }
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IN );
+    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
+      Expr *pRight = pTerm->pExpr->pRight;
+      if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
+        VdbeCoverage(v);
+      }
+      if( zAff ){
+        if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+        if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
+          zAff[j] = SQLITE_AFF_BLOB;
+        }
+      }
+    }
+  }
+  *pzAff = zAff;
+  return regBase;
+}
+
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+/*
+** If the most recently coded instruction is a constant range contraint
+** that originated from the LIKE optimization, then change the P3 to be
+** pLoop->iLikeRepCntr and set P5.
+**
+** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
+** expression: "x>='ABC' AND x<'abd'".  But this requires that the range
+** scan loop run twice, once for strings and a second time for BLOBs.
+** The OP_String opcodes on the second pass convert the upper and lower
+** bound string contants to blobs.  This routine makes the necessary changes
+** to the OP_String opcodes for that to happen.
+**
+** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
+** only the one pass through the string space is required, so this routine
+** becomes a no-op.
+*/
+static void whereLikeOptimizationStringFixup(
+  Vdbe *v,                /* prepared statement under construction */
+  WhereLevel *pLevel,     /* The loop that contains the LIKE operator */
+  WhereTerm *pTerm        /* The upper or lower bound just coded */
+){
+  if( pTerm->wtFlags & TERM_LIKEOPT ){
+    VdbeOp *pOp;
+    assert( pLevel->iLikeRepCntr>0 );
+    pOp = sqlite3VdbeGetOp(v, -1);
+    assert( pOp!=0 );
+    assert( pOp->opcode==OP_String8 
+            || pTerm->pWC->pWInfo->pParse->db->mallocFailed );
+    pOp->p3 = pLevel->iLikeRepCntr;
+    pOp->p5 = 1;
+  }
+}
+#else
+# define whereLikeOptimizationStringFixup(A,B,C)
+#endif
+
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+/*
+** Information is passed from codeCursorHint() down to individual nodes of
+** the expression tree (by sqlite3WalkExpr()) using an instance of this
+** structure.
+*/
+struct CCurHint {
+  int iTabCur;    /* Cursor for the main table */
+  int iIdxCur;    /* Cursor for the index, if pIdx!=0.  Unused otherwise */
+  Index *pIdx;    /* The index used to access the table */
+};
+
+/*
+** This function is called for every node of an expression that is a candidate
+** for a cursor hint on an index cursor.  For TK_COLUMN nodes that reference
+** the table CCurHint.iTabCur, verify that the same column can be
+** accessed through the index.  If it cannot, then set pWalker->eCode to 1.
+*/
+static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  assert( pHint->pIdx!=0 );
+  if( pExpr->op==TK_COLUMN
+   && pExpr->iTable==pHint->iTabCur
+   && sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn)<0
+  ){
+    pWalker->eCode = 1;
+  }
+  return WRC_Continue;
+}
+
+
+/*
+** This function is called on every node of an expression tree used as an
+** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN
+** that accesses any table other than the one identified by
+** CCurHint.iTabCur, then do the following:
+**
+**   1) allocate a register and code an OP_Column instruction to read 
+**      the specified column into the new register, and
+**
+**   2) transform the expression node to a TK_REGISTER node that reads 
+**      from the newly populated register.
+**
+** Also, if the node is a TK_COLUMN that does access the table idenified
+** by pCCurHint.iTabCur, and an index is being used (which we will
+** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
+** an access of the index rather than the original table.
+*/
+static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
+  int rc = WRC_Continue;
+  struct CCurHint *pHint = pWalker->u.pCCurHint;
+  if( pExpr->op==TK_COLUMN ){
+    if( pExpr->iTable!=pHint->iTabCur ){
+      Vdbe *v = pWalker->pParse->pVdbe;
+      int reg = ++pWalker->pParse->nMem;   /* Register for column value */
+      sqlite3ExprCodeGetColumnOfTable(
+          v, pExpr->pTab, pExpr->iTable, pExpr->iColumn, reg
+      );
+      pExpr->op = TK_REGISTER;
+      pExpr->iTable = reg;
+    }else if( pHint->pIdx!=0 ){
+      pExpr->iTable = pHint->iIdxCur;
+      pExpr->iColumn = sqlite3ColumnOfIndex(pHint->pIdx, pExpr->iColumn);
+      assert( pExpr->iColumn>=0 );
+    }
+  }else if( pExpr->op==TK_AGG_FUNCTION ){
+    /* An aggregate function in the WHERE clause of a query means this must
+    ** be a correlated sub-query, and expression pExpr is an aggregate from
+    ** the parent context. Do not walk the function arguments in this case.
+    **
+    ** todo: It should be possible to replace this node with a TK_REGISTER
+    ** expression, as the result of the expression must be stored in a 
+    ** register at this point. The same holds for TK_AGG_COLUMN nodes. */
+    rc = WRC_Prune;
+  }
+  return rc;
+}
+
+/*
+** Insert an OP_CursorHint instruction if it is appropriate to do so.
+*/
+static void codeCursorHint(
+  WhereInfo *pWInfo,    /* The where clause */
+  WhereLevel *pLevel,   /* Which loop to provide hints for */
+  WhereTerm *pEndRange  /* Hint this end-of-scan boundary term if not NULL */
+){
+  Parse *pParse = pWInfo->pParse;
+  sqlite3 *db = pParse->db;
+  Vdbe *v = pParse->pVdbe;
+  Expr *pExpr = 0;
+  WhereLoop *pLoop = pLevel->pWLoop;
+  int iCur;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  int i, j;
+  struct CCurHint sHint;
+  Walker sWalker;
+
+  if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;
+  iCur = pLevel->iTabCur;
+  assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );
+  sHint.iTabCur = iCur;
+  sHint.iIdxCur = pLevel->iIdxCur;
+  sHint.pIdx = pLoop->u.btree.pIndex;
+  memset(&sWalker, 0, sizeof(sWalker));
+  sWalker.pParse = pParse;
+  sWalker.u.pCCurHint = &sHint;
+  pWC = &pWInfo->sWC;
+  for(i=0; i<pWC->nTerm; i++){
+    pTerm = &pWC->a[i];
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( pTerm->prereqAll & pLevel->notReady ) continue;
+    if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
+
+    /* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
+    ** the cursor.  These terms are not needed as hints for a pure range
+    ** scan (that has no == terms) so omit them. */
+    if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){
+      for(j=0; j<pLoop->nLTerm && pLoop->aLTerm[j]!=pTerm; j++){}
+      if( j<pLoop->nLTerm ) continue;
+    }
+
+    /* No subqueries or non-deterministic functions allowed */
+    if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;
+
+    /* For an index scan, make sure referenced columns are actually in
+    ** the index. */
+    if( sHint.pIdx!=0 ){
+      sWalker.eCode = 0;
+      sWalker.xExprCallback = codeCursorHintCheckExpr;
+      sqlite3WalkExpr(&sWalker, pTerm->pExpr);
+      if( sWalker.eCode ) continue;
+    }
+
+    /* If we survive all prior tests, that means this term is worth hinting */
+    pExpr = sqlite3ExprAnd(db, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
+  }
+  if( pExpr!=0 ){
+    sWalker.xExprCallback = codeCursorHintFixExpr;
+    sqlite3WalkExpr(&sWalker, pExpr);
+    sqlite3VdbeAddOp4(v, OP_CursorHint, 
+                      (sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
+                      (const char*)pExpr, P4_EXPR);
+  }
+}
+#else
+# define codeCursorHint(A,B,C)  /* No-op */
+#endif /* SQLITE_ENABLE_CURSOR_HINTS */
+
+/*
+** Generate code for the start of the iLevel-th loop in the WHERE clause
+** implementation described by pWInfo.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
+  WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
+  int iLevel,          /* Which level of pWInfo->a[] should be coded */
+  Bitmask notReady     /* Which tables are currently available */
+){
+  int j, k;            /* Loop counters */
+  int iCur;            /* The VDBE cursor for the table */
+  int addrNxt;         /* Where to jump to continue with the next IN case */
+  int omitTable;       /* True if we use the index only */
+  int bRev;            /* True if we need to scan in reverse order */
+  WhereLevel *pLevel;  /* The where level to be coded */
+  WhereLoop *pLoop;    /* The WhereLoop object being coded */
+  WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
+  WhereTerm *pTerm;               /* A WHERE clause term */
+  Parse *pParse;                  /* Parsing context */
+  sqlite3 *db;                    /* Database connection */
+  Vdbe *v;                        /* The prepared stmt under constructions */
+  struct SrcList_item *pTabItem;  /* FROM clause term being coded */
+  int addrBrk;                    /* Jump here to break out of the loop */
+  int addrCont;                   /* Jump here to continue with next cycle */
+  int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
+  int iReleaseReg = 0;      /* Temp register to free before returning */
+
+  pParse = pWInfo->pParse;
+  v = pParse->pVdbe;
+  pWC = &pWInfo->sWC;
+  db = pParse->db;
+  pLevel = &pWInfo->a[iLevel];
+  pLoop = pLevel->pWLoop;
+  pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
+  iCur = pTabItem->iCursor;
+  pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+  bRev = (pWInfo->revMask>>iLevel)&1;
+  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
+           && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
+  VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
+
+  /* Create labels for the "break" and "continue" instructions
+  ** for the current loop.  Jump to addrBrk to break out of a loop.
+  ** Jump to cont to go immediately to the next iteration of the
+  ** loop.
+  **
+  ** When there is an IN operator, we also have a "addrNxt" label that
+  ** means to continue with the next IN value combination.  When
+  ** there are no IN operators in the constraints, the "addrNxt" label
+  ** is the same as "addrBrk".
+  */
+  addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
+  addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(v);
+
+  /* If this is the right table of a LEFT OUTER JOIN, allocate and
+  ** initialize a memory cell that records if this table matches any
+  ** row of the left table of the join.
+  */
+  if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
+    pLevel->iLeftJoin = ++pParse->nMem;
+    sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
+    VdbeComment((v, "init LEFT JOIN no-match flag"));
+  }
+
+  /* Special case of a FROM clause subquery implemented as a co-routine */
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    pLevel->p2 =  sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+    pLevel->op = OP_Goto;
+  }else
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
+    **          to access the data.
+    */
+    int iReg;   /* P3 Value for OP_VFilter */
+    int addrNotFound;
+    int nConstraint = pLoop->nLTerm;
+
+    sqlite3ExprCachePush(pParse);
+    iReg = sqlite3GetTempRange(pParse, nConstraint+2);
+    addrNotFound = pLevel->addrBrk;
+    for(j=0; j<nConstraint; j++){
+      int iTarget = iReg+j+2;
+      pTerm = pLoop->aLTerm[j];
+      if( pTerm==0 ) continue;
+      if( pTerm->eOperator & WO_IN ){
+        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+        addrNotFound = pLevel->addrNxt;
+      }else{
+        sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
+      }
+    }
+    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+                      pLoop->u.vtab.idxStr,
+                      pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
+    VdbeCoverage(v);
+    pLoop->u.vtab.needFree = 0;
+    for(j=0; j<nConstraint && j<16; j++){
+      if( (pLoop->u.vtab.omitMask>>j)&1 ){
+        disableTerm(pLevel, pLoop->aLTerm[j]);
+      }
+    }
+    pLevel->p1 = iCur;
+    pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+    sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
+    sqlite3ExprCachePop(pParse);
+  }else
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+  if( (pLoop->wsFlags & WHERE_IPK)!=0
+   && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+  ){
+    /* Case 2:  We can directly reference a single row using an
+    **          equality comparison against the ROWID field.  Or
+    **          we reference multiple rows using a "rowid IN (...)"
+    **          construct.
+    */
+    assert( pLoop->u.btree.nEq==1 );
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->pExpr!=0 );
+    assert( omitTable==0 );
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    iReleaseReg = ++pParse->nMem;
+    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
+    if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
+    addrNxt = pLevel->addrNxt;
+    sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
+    VdbeCoverage(v);
+    sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1);
+    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+    VdbeComment((v, "pk"));
+    pLevel->op = OP_Noop;
+  }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+         && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+  ){
+    /* Case 3:  We have an inequality comparison against the ROWID field.
+    */
+    int testOp = OP_Noop;
+    int start;
+    int memEndValue = 0;
+    WhereTerm *pStart, *pEnd;
+
+    assert( omitTable==0 );
+    j = 0;
+    pStart = pEnd = 0;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+    assert( pStart!=0 || pEnd!=0 );
+    if( bRev ){
+      pTerm = pStart;
+      pStart = pEnd;
+      pEnd = pTerm;
+    }
+    codeCursorHint(pWInfo, pLevel, pEnd);
+    if( pStart ){
+      Expr *pX;             /* The expression that defines the start bound */
+      int r1, rTemp;        /* Registers for holding the start boundary */
+
+      /* The following constant maps TK_xx codes into corresponding 
+      ** seek opcodes.  It depends on a particular ordering of TK_xx
+      */
+      const u8 aMoveOp[] = {
+           /* TK_GT */  OP_SeekGT,
+           /* TK_LE */  OP_SeekLE,
+           /* TK_LT */  OP_SeekLT,
+           /* TK_GE */  OP_SeekGE
+      };
+      assert( TK_LE==TK_GT+1 );      /* Make sure the ordering.. */
+      assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
+      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
+
+      assert( (pStart->wtFlags & TERM_VNULL)==0 );
+      testcase( pStart->wtFlags & TERM_VIRTUAL );
+      pX = pStart->pExpr;
+      assert( pX!=0 );
+      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
+      r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
+      sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
+      VdbeComment((v, "pk"));
+      VdbeCoverageIf(v, pX->op==TK_GT);
+      VdbeCoverageIf(v, pX->op==TK_LE);
+      VdbeCoverageIf(v, pX->op==TK_LT);
+      VdbeCoverageIf(v, pX->op==TK_GE);
+      sqlite3ExprCacheAffinityChange(pParse, r1, 1);
+      sqlite3ReleaseTempReg(pParse, rTemp);
+      disableTerm(pLevel, pStart);
+    }else{
+      sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+    }
+    if( pEnd ){
+      Expr *pX;
+      pX = pEnd->pExpr;
+      assert( pX!=0 );
+      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
+      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
+      testcase( pEnd->wtFlags & TERM_VIRTUAL );
+      memEndValue = ++pParse->nMem;
+      sqlite3ExprCode(pParse, pX->pRight, memEndValue);
+      if( pX->op==TK_LT || pX->op==TK_GT ){
+        testOp = bRev ? OP_Le : OP_Ge;
+      }else{
+        testOp = bRev ? OP_Lt : OP_Gt;
+      }
+      disableTerm(pLevel, pEnd);
+    }
+    start = sqlite3VdbeCurrentAddr(v);
+    pLevel->op = bRev ? OP_Prev : OP_Next;
+    pLevel->p1 = iCur;
+    pLevel->p2 = start;
+    assert( pLevel->p5==0 );
+    if( testOp!=OP_Noop ){
+      iRowidReg = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
+      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
+      VdbeCoverageIf(v, testOp==OP_Le);
+      VdbeCoverageIf(v, testOp==OP_Lt);
+      VdbeCoverageIf(v, testOp==OP_Ge);
+      VdbeCoverageIf(v, testOp==OP_Gt);
+      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
+    }
+  }else if( pLoop->wsFlags & WHERE_INDEXED ){
+    /* Case 4: A scan using an index.
+    **
+    **         The WHERE clause may contain zero or more equality 
+    **         terms ("==" or "IN" operators) that refer to the N
+    **         left-most columns of the index. It may also contain
+    **         inequality constraints (>, <, >= or <=) on the indexed
+    **         column that immediately follows the N equalities. Only 
+    **         the right-most column can be an inequality - the rest must
+    **         use the "==" and "IN" operators. For example, if the 
+    **         index is on (x,y,z), then the following clauses are all 
+    **         optimized:
+    **
+    **            x=5
+    **            x=5 AND y=10
+    **            x=5 AND y<10
+    **            x=5 AND y>5 AND y<10
+    **            x=5 AND y=5 AND z<=10
+    **
+    **         The z<10 term of the following cannot be used, only
+    **         the x=5 term:
+    **
+    **            x=5 AND z<10
+    **
+    **         N may be zero if there are inequality constraints.
+    **         If there are no inequality constraints, then N is at
+    **         least one.
+    **
+    **         This case is also used when there are no WHERE clause
+    **         constraints but an index is selected anyway, in order
+    **         to force the output order to conform to an ORDER BY.
+    */  
+    static const u8 aStartOp[] = {
+      0,
+      0,
+      OP_Rewind,           /* 2: (!start_constraints && startEq &&  !bRev) */
+      OP_Last,             /* 3: (!start_constraints && startEq &&   bRev) */
+      OP_SeekGT,           /* 4: (start_constraints  && !startEq && !bRev) */
+      OP_SeekLT,           /* 5: (start_constraints  && !startEq &&  bRev) */
+      OP_SeekGE,           /* 6: (start_constraints  &&  startEq && !bRev) */
+      OP_SeekLE            /* 7: (start_constraints  &&  startEq &&  bRev) */
+    };
+    static const u8 aEndOp[] = {
+      OP_IdxGE,            /* 0: (end_constraints && !bRev && !endEq) */
+      OP_IdxGT,            /* 1: (end_constraints && !bRev &&  endEq) */
+      OP_IdxLE,            /* 2: (end_constraints &&  bRev && !endEq) */
+      OP_IdxLT,            /* 3: (end_constraints &&  bRev &&  endEq) */
+    };
+    u16 nEq = pLoop->u.btree.nEq;     /* Number of == or IN terms */
+    int regBase;                 /* Base register holding constraint values */
+    WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
+    WhereTerm *pRangeEnd = 0;    /* Inequality constraint at range end */
+    int startEq;                 /* True if range start uses ==, >= or <= */
+    int endEq;                   /* True if range end uses ==, >= or <= */
+    int start_constraints;       /* Start of range is constrained */
+    int nConstraint;             /* Number of constraint terms */
+    Index *pIdx;                 /* The index we will be using */
+    int iIdxCur;                 /* The VDBE cursor for the index */
+    int nExtraReg = 0;           /* Number of extra registers needed */
+    int op;                      /* Instruction opcode */
+    char *zStartAff;             /* Affinity for start of range constraint */
+    char cEndAff = 0;            /* Affinity for end of range constraint */
+    u8 bSeekPastNull = 0;        /* True to seek past initial nulls */
+    u8 bStopAtNull = 0;          /* Add condition to terminate at NULLs */
+
+    pIdx = pLoop->u.btree.pIndex;
+    iIdxCur = pLevel->iIdxCur;
+    assert( nEq>=pLoop->nSkip );
+
+    /* If this loop satisfies a sort order (pOrderBy) request that 
+    ** was passed to this function to implement a "SELECT min(x) ..." 
+    ** query, then the caller will only allow the loop to run for
+    ** a single iteration. This means that the first row returned
+    ** should not have a NULL value stored in 'x'. If column 'x' is
+    ** the first one after the nEq equality constraints in the index,
+    ** this requires some special handling.
+    */
+    assert( pWInfo->pOrderBy==0
+         || pWInfo->pOrderBy->nExpr==1
+         || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 );
+    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+     && pWInfo->nOBSat>0
+     && (pIdx->nKeyCol>nEq)
+    ){
+      assert( pLoop->nSkip==0 );
+      bSeekPastNull = 1;
+      nExtraReg = 1;
+    }
+
+    /* Find any inequality constraint terms for the start and end 
+    ** of the range. 
+    */
+    j = nEq;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+      pRangeStart = pLoop->aLTerm[j++];
+      nExtraReg = 1;
+      /* Like optimization range constraints always occur in pairs */
+      assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 || 
+              (pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
+    }
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+      pRangeEnd = pLoop->aLTerm[j++];
+      nExtraReg = 1;
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+      if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
+        assert( pRangeStart!=0 );                     /* LIKE opt constraints */
+        assert( pRangeStart->wtFlags & TERM_LIKEOPT );   /* occur in pairs */
+        pLevel->iLikeRepCntr = ++pParse->nMem;
+        testcase( bRev );
+        testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
+        sqlite3VdbeAddOp2(v, OP_Integer,
+                          bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC),
+                          pLevel->iLikeRepCntr);
+        VdbeComment((v, "LIKE loop counter"));
+        pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
+      }
+#endif
+      if( pRangeStart==0
+       && (j = pIdx->aiColumn[nEq])>=0 
+       && pIdx->pTable->aCol[j].notNull==0
+      ){
+        bSeekPastNull = 1;
+      }
+    }
+    assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
+
+    /* If we are doing a reverse order scan on an ascending index, or
+    ** a forward order scan on a descending index, interchange the 
+    ** start and end terms (pRangeStart and pRangeEnd).
+    */
+    if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
+     || (bRev && pIdx->nKeyCol==nEq)
+    ){
+      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
+      SWAP(u8, bSeekPastNull, bStopAtNull);
+    }
+
+    /* Generate code to evaluate all constraint terms using == or IN
+    ** and store the values of those terms in an array of registers
+    ** starting at regBase.
+    */
+    codeCursorHint(pWInfo, pLevel, pRangeEnd);
+    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
+    assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
+    if( zStartAff ) cEndAff = zStartAff[nEq];
+    addrNxt = pLevel->addrNxt;
+
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
+    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
+    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
+    start_constraints = pRangeStart || nEq>0;
+
+    /* Seek the index cursor to the start of the range. */
+    nConstraint = nEq;
+    if( pRangeStart ){
+      Expr *pRight = pRangeStart->pExpr->pRight;
+      sqlite3ExprCode(pParse, pRight, regBase+nEq);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
+      if( (pRangeStart->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
+      }
+      if( zStartAff ){
+        if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_BLOB){
+          /* Since the comparison is to be performed with no conversions
+          ** applied to the operands, set the affinity to apply to pRight to 
+          ** SQLITE_AFF_BLOB.  */
+          zStartAff[nEq] = SQLITE_AFF_BLOB;
+        }
+        if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
+          zStartAff[nEq] = SQLITE_AFF_BLOB;
+        }
+      }  
+      nConstraint++;
+      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
+    }else if( bSeekPastNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      nConstraint++;
+      startEq = 0;
+      start_constraints = 1;
+    }
+    codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
+    op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
+    assert( op!=0 );
+    sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+    VdbeCoverage(v);
+    VdbeCoverageIf(v, op==OP_Rewind);  testcase( op==OP_Rewind );
+    VdbeCoverageIf(v, op==OP_Last);    testcase( op==OP_Last );
+    VdbeCoverageIf(v, op==OP_SeekGT);  testcase( op==OP_SeekGT );
+    VdbeCoverageIf(v, op==OP_SeekGE);  testcase( op==OP_SeekGE );
+    VdbeCoverageIf(v, op==OP_SeekLE);  testcase( op==OP_SeekLE );
+    VdbeCoverageIf(v, op==OP_SeekLT);  testcase( op==OP_SeekLT );
+
+    /* Load the value for the inequality constraint at the end of the
+    ** range (if any).
+    */
+    nConstraint = nEq;
+    if( pRangeEnd ){
+      Expr *pRight = pRangeEnd->pExpr->pRight;
+      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
+      sqlite3ExprCode(pParse, pRight, regBase+nEq);
+      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
+      if( (pRangeEnd->wtFlags & TERM_VNULL)==0
+       && sqlite3ExprCanBeNull(pRight)
+      ){
+        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
+        VdbeCoverage(v);
+      }
+      if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_BLOB
+       && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
+      ){
+        codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
+      }
+      nConstraint++;
+      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
+    }else if( bStopAtNull ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
+      endEq = 0;
+      nConstraint++;
+    }
+    sqlite3DbFree(db, zStartAff);
+
+    /* Top of the loop body */
+    pLevel->p2 = sqlite3VdbeCurrentAddr(v);
+
+    /* Check if the index cursor is past the end of the range. */
+    if( nConstraint ){
+      op = aEndOp[bRev*2 + endEq];
+      sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
+      testcase( op==OP_IdxGT );  VdbeCoverageIf(v, op==OP_IdxGT );
+      testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
+      testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
+      testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
+    }
+
+    /* Seek the table cursor, if required */
+    disableTerm(pLevel, pRangeStart);
+    disableTerm(pLevel, pRangeEnd);
+    if( omitTable ){
+      /* pIdx is a covering index.  No need to access the main table. */
+    }else if( HasRowid(pIdx->pTable) ){
+      iRowidReg = ++pParse->nMem;
+      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
+      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
+      if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowidReg);
+        VdbeCoverage(v);
+      }else{
+        sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
+      }
+    }else if( iCur!=iIdxCur ){
+      Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
+      iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
+      for(j=0; j<pPk->nKeyCol; j++){
+        k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]);
+        sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
+      }
+      sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
+                           iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
+    }
+
+    /* Record the instruction used to terminate the loop. Disable 
+    ** WHERE clause terms made redundant by the index range scan.
+    */
+    if( pLoop->wsFlags & WHERE_ONEROW ){
+      pLevel->op = OP_Noop;
+    }else if( bRev ){
+      pLevel->op = OP_Prev;
+    }else{
+      pLevel->op = OP_Next;
+    }
+    pLevel->p1 = iIdxCur;
+    pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
+    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }else{
+      assert( pLevel->p5==0 );
+    }
+  }else
+
+#ifndef SQLITE_OMIT_OR_OPTIMIZATION
+  if( pLoop->wsFlags & WHERE_MULTI_OR ){
+    /* Case 5:  Two or more separately indexed terms connected by OR
+    **
+    ** Example:
+    **
+    **   CREATE TABLE t1(a,b,c,d);
+    **   CREATE INDEX i1 ON t1(a);
+    **   CREATE INDEX i2 ON t1(b);
+    **   CREATE INDEX i3 ON t1(c);
+    **
+    **   SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
+    **
+    ** In the example, there are three indexed terms connected by OR.
+    ** The top of the loop looks like this:
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **
+    ** Then, for each indexed term, the following. The arguments to
+    ** RowSetTest are such that the rowid of the current row is inserted
+    ** into the RowSet. If it is already present, control skips the
+    ** Gosub opcode and jumps straight to the code generated by WhereEnd().
+    **
+    **        sqlite3WhereBegin(<term>)
+    **          RowSetTest                  # Insert rowid into rowset
+    **          Gosub      2 A
+    **        sqlite3WhereEnd()
+    **
+    ** Following the above, code to terminate the loop. Label A, the target
+    ** of the Gosub above, jumps to the instruction right after the Goto.
+    **
+    **          Null       1                # Zero the rowset in reg 1
+    **          Goto       B                # The loop is finished.
+    **
+    **       A: <loop body>                 # Return data, whatever.
+    **
+    **          Return     2                # Jump back to the Gosub
+    **
+    **       B: <after the loop>
+    **
+    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
+    ** use an ephemeral index instead of a RowSet to record the primary
+    ** keys of the rows we have already seen.
+    **
+    */
+    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
+    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
+    Index *pCov = 0;             /* Potential covering index (or NULL) */
+    int iCovCur = pParse->nTab++;  /* Cursor used for index scans (if any) */
+
+    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
+    int regRowset = 0;                        /* Register for RowSet object */
+    int regRowid = 0;                         /* Register holding rowid */
+    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
+    int iRetInit;                             /* Address of regReturn init */
+    int untestedTerms = 0;             /* Some terms not completely tested */
+    int ii;                            /* Loop counter */
+    u16 wctrlFlags;                    /* Flags for sub-WHERE clause */
+    Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
+    Table *pTab = pTabItem->pTab;
+   
+    pTerm = pLoop->aLTerm[0];
+    assert( pTerm!=0 );
+    assert( pTerm->eOperator & WO_OR );
+    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
+    pOrWc = &pTerm->u.pOrInfo->wc;
+    pLevel->op = OP_Return;
+    pLevel->p1 = regReturn;
+
+    /* Set up a new SrcList in pOrTab containing the table being scanned
+    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
+    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
+    */
+    if( pWInfo->nLevel>1 ){
+      int nNotReady;                 /* The number of notReady tables */
+      struct SrcList_item *origSrc;     /* Original list of tables */
+      nNotReady = pWInfo->nLevel - iLevel - 1;
+      pOrTab = sqlite3StackAllocRaw(db,
+                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
+      if( pOrTab==0 ) return notReady;
+      pOrTab->nAlloc = (u8)(nNotReady + 1);
+      pOrTab->nSrc = pOrTab->nAlloc;
+      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
+      origSrc = pWInfo->pTabList->a;
+      for(k=1; k<=nNotReady; k++){
+        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
+      }
+    }else{
+      pOrTab = pWInfo->pTabList;
+    }
+
+    /* Initialize the rowset register to contain NULL. An SQL NULL is 
+    ** equivalent to an empty rowset.  Or, create an ephemeral index
+    ** capable of holding primary keys in the case of a WITHOUT ROWID.
+    **
+    ** Also initialize regReturn to contain the address of the instruction 
+    ** immediately following the OP_Return at the bottom of the loop. This
+    ** is required in a few obscure LEFT JOIN cases where control jumps
+    ** over the top of the loop into the body of it. In this case the 
+    ** correct response for the end-of-loop code (the OP_Return) is to 
+    ** fall through to the next instruction, just as an OP_Next does if
+    ** called on an uninitialized cursor.
+    */
+    if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+      if( HasRowid(pTab) ){
+        regRowset = ++pParse->nMem;
+        sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
+      }else{
+        Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+        regRowset = pParse->nTab++;
+        sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
+        sqlite3VdbeSetP4KeyInfo(pParse, pPk);
+      }
+      regRowid = ++pParse->nMem;
+    }
+    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
+
+    /* If the original WHERE clause is z of the form:  (x1 OR x2 OR ...) AND y
+    ** Then for every term xN, evaluate as the subexpression: xN AND z
+    ** That way, terms in y that are factored into the disjunction will
+    ** be picked up by the recursive calls to sqlite3WhereBegin() below.
+    **
+    ** Actually, each subexpression is converted to "xN AND w" where w is
+    ** the "interesting" terms of z - terms that did not originate in the
+    ** ON or USING clause of a LEFT JOIN, and terms that are usable as 
+    ** indices.
+    **
+    ** This optimization also only applies if the (x1 OR x2 OR ...) term
+    ** is not contained in the ON clause of a LEFT JOIN.
+    ** See ticket http://www.sqlite.org/src/info/f2369304e4
+    */
+    if( pWC->nTerm>1 ){
+      int iTerm;
+      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
+        Expr *pExpr = pWC->a[iTerm].pExpr;
+        if( &pWC->a[iTerm] == pTerm ) continue;
+        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
+        if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;
+        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
+        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
+        pExpr = sqlite3ExprDup(db, pExpr, 0);
+        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
+      }
+      if( pAndExpr ){
+        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr, 0);
+      }
+    }
+
+    /* Run a separate WHERE clause for each term of the OR clause.  After
+    ** eliminating duplicates from other WHERE clauses, the action for each
+    ** sub-WHERE clause is to to invoke the main loop body as a subroutine.
+    */
+    wctrlFlags =  WHERE_OMIT_OPEN_CLOSE
+                | WHERE_FORCE_TABLE
+                | WHERE_ONETABLE_ONLY
+                | WHERE_NO_AUTOINDEX;
+    for(ii=0; ii<pOrWc->nTerm; ii++){
+      WhereTerm *pOrTerm = &pOrWc->a[ii];
+      if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
+        WhereInfo *pSubWInfo;           /* Info for single OR-term scan */
+        Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
+        int jmp1 = 0;                   /* Address of jump operation */
+        if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
+          pAndExpr->pLeft = pOrExpr;
+          pOrExpr = pAndExpr;
+        }
+        /* Loop through table entries that match term pOrTerm. */
+        WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
+        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
+                                      wctrlFlags, iCovCur);
+        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
+        if( pSubWInfo ){
+          WhereLoop *pSubLoop;
+          int addrExplain = sqlite3WhereExplainOneScan(
+              pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
+          );
+          sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
+
+          /* This is the sub-WHERE clause body.  First skip over
+          ** duplicate rows from prior sub-WHERE clauses, and record the
+          ** rowid (or PRIMARY KEY) for the current row so that the same
+          ** row will be skipped in subsequent sub-WHERE clauses.
+          */
+          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+            int r;
+            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
+            if( HasRowid(pTab) ){
+              r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
+              jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,
+                                           r,iSet);
+              VdbeCoverage(v);
+            }else{
+              Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+              int nPk = pPk->nKeyCol;
+              int iPk;
+
+              /* Read the PK into an array of temp registers. */
+              r = sqlite3GetTempRange(pParse, nPk);
+              for(iPk=0; iPk<nPk; iPk++){
+                int iCol = pPk->aiColumn[iPk];
+                sqlite3ExprCodeGetColumnToReg(pParse, pTab, iCol, iCur, r+iPk);
+              }
+
+              /* Check if the temp table already contains this key. If so,
+              ** the row has already been included in the result set and
+              ** can be ignored (by jumping past the Gosub below). Otherwise,
+              ** insert the key into the temp table and proceed with processing
+              ** the row.
+              **
+              ** Use some of the same optimizations as OP_RowSetTest: If iSet
+              ** is zero, assume that the key cannot already be present in
+              ** the temp table. And if iSet is -1, assume that there is no 
+              ** need to insert the key into the temp table, as it will never 
+              ** be tested for.  */ 
+              if( iSet ){
+                jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
+                VdbeCoverage(v);
+              }
+              if( iSet>=0 ){
+                sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
+                sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0);
+                if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+              }
+
+              /* Release the array of temp registers */
+              sqlite3ReleaseTempRange(pParse, r, nPk);
+            }
+          }
+
+          /* Invoke the main loop body as a subroutine */
+          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+
+          /* Jump here (skipping the main loop body subroutine) if the
+          ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
+          if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);
+
+          /* The pSubWInfo->untestedTerms flag means that this OR term
+          ** contained one or more AND term from a notReady table.  The
+          ** terms from the notReady table could not be tested and will
+          ** need to be tested later.
+          */
+          if( pSubWInfo->untestedTerms ) untestedTerms = 1;
+
+          /* If all of the OR-connected terms are optimized using the same
+          ** index, and the index is opened using the same cursor number
+          ** by each call to sqlite3WhereBegin() made by this loop, it may
+          ** be possible to use that index as a covering index.
+          **
+          ** If the call to sqlite3WhereBegin() above resulted in a scan that
+          ** uses an index, and this is either the first OR-connected term
+          ** processed or the index is the same as that used by all previous
+          ** terms, set pCov to the candidate covering index. Otherwise, set 
+          ** pCov to NULL to indicate that no candidate covering index will 
+          ** be available.
+          */
+          pSubLoop = pSubWInfo->a[0].pWLoop;
+          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
+           && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
+          ){
+            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+            pCov = pSubLoop->u.btree.pIndex;
+            wctrlFlags |= WHERE_REOPEN_IDX;
+          }else{
+            pCov = 0;
+          }
+
+          /* Finish the loop through table entries that match term pOrTerm. */
+          sqlite3WhereEnd(pSubWInfo);
+        }
+      }
+    }
+    pLevel->u.pCovidx = pCov;
+    if( pCov ) pLevel->iIdxCur = iCovCur;
+    if( pAndExpr ){
+      pAndExpr->pLeft = 0;
+      sqlite3ExprDelete(db, pAndExpr);
+    }
+    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
+    sqlite3VdbeGoto(v, pLevel->addrBrk);
+    sqlite3VdbeResolveLabel(v, iLoopBody);
+
+    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
+    if( !untestedTerms ) disableTerm(pLevel, pTerm);
+  }else
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+  {
+    /* Case 6:  There is no usable index.  We must do a complete
+    **          scan of the entire table.
+    */
+    static const u8 aStep[] = { OP_Next, OP_Prev };
+    static const u8 aStart[] = { OP_Rewind, OP_Last };
+    assert( bRev==0 || bRev==1 );
+    if( pTabItem->fg.isRecursive ){
+      /* Tables marked isRecursive have only a single row that is stored in
+      ** a pseudo-cursor.  No need to Rewind or Next such cursors. */
+      pLevel->op = OP_Noop;
+    }else{
+      codeCursorHint(pWInfo, pLevel, 0);
+      pLevel->op = aStep[bRev];
+      pLevel->p1 = iCur;
+      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
+      VdbeCoverageIf(v, bRev==0);
+      VdbeCoverageIf(v, bRev!=0);
+      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
+    }
+  }
+
+#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+  pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
+#endif
+
+  /* Insert code to test every subexpression that can be completely
+  ** computed using the current set of tables.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE;
+    int skipLikeAddr = 0;
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    testcase( pTerm->wtFlags & TERM_CODED );
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+      testcase( pWInfo->untestedTerms==0
+               && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
+      pWInfo->untestedTerms = 1;
+      continue;
+    }
+    pE = pTerm->pExpr;
+    assert( pE!=0 );
+    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
+      continue;
+    }
+    if( pTerm->wtFlags & TERM_LIKECOND ){
+#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+      continue;
+#else
+      assert( pLevel->iLikeRepCntr>0 );
+      skipLikeAddr = sqlite3VdbeAddOp1(v, OP_IfNot, pLevel->iLikeRepCntr);
+      VdbeCoverage(v);
+#endif
+    }
+    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
+    if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
+    pTerm->wtFlags |= TERM_CODED;
+  }
+
+  /* Insert code to test for implied constraints based on transitivity
+  ** of the "==" operator.
+  **
+  ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
+  ** and we are coding the t1 loop and the t2 loop has not yet coded,
+  ** then we cannot use the "t1.a=t2.b" constraint, but we can code
+  ** the implied "t1.a=123" constraint.
+  */
+  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
+    Expr *pE, *pEAlt;
+    WhereTerm *pAlt;
+    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+    if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
+    if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
+    if( pTerm->leftCursor!=iCur ) continue;
+    if( pLevel->iLeftJoin ) continue;
+    pE = pTerm->pExpr;
+    assert( !ExprHasProperty(pE, EP_FromJoin) );
+    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
+    pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.leftColumn, notReady,
+                    WO_EQ|WO_IN|WO_IS, 0);
+    if( pAlt==0 ) continue;
+    if( pAlt->wtFlags & (TERM_CODED) ) continue;
+    testcase( pAlt->eOperator & WO_EQ );
+    testcase( pAlt->eOperator & WO_IS );
+    testcase( pAlt->eOperator & WO_IN );
+    VdbeModuleComment((v, "begin transitive constraint"));
+    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
+    if( pEAlt ){
+      *pEAlt = *pAlt->pExpr;
+      pEAlt->pLeft = pE->pLeft;
+      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
+      sqlite3StackFree(db, pEAlt);
+    }
+  }
+
+  /* For a LEFT OUTER JOIN, generate code that will record the fact that
+  ** at least one row of the right table has matched the left table.  
+  */
+  if( pLevel->iLeftJoin ){
+    pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
+    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
+    VdbeComment((v, "record LEFT JOIN hit"));
+    sqlite3ExprCacheClear(pParse);
+    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
+      testcase( pTerm->wtFlags & TERM_CODED );
+      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
+        assert( pWInfo->untestedTerms );
+        continue;
+      }
+      assert( pTerm->pExpr );
+      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
+      pTerm->wtFlags |= TERM_CODED;
+    }
+  }
+
+  return pLevel->notReady;
+}
+
+/************** End of wherecode.c *******************************************/
+/************** Begin file whereexpr.c ***************************************/
+/*
+** 2015-06-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.
+**
+** This file was originally part of where.c but was split out to improve
+** readability and editabiliity.  This file contains utility routines for
+** analyzing Expr objects in the WHERE clause.
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declarations */
+static void exprAnalyze(SrcList*, WhereClause*, int);
+
+/*
+** Deallocate all memory associated with a WhereOrInfo object.
+*/
+static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Deallocate all memory associated with a WhereAndInfo object.
+*/
+static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
+  sqlite3WhereClauseClear(&p->wc);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Add a single new WhereTerm entry to the WhereClause object pWC.
+** The new WhereTerm object is constructed from Expr p and with wtFlags.
+** The index in pWC->a[] of the new WhereTerm is returned on success.
+** 0 is returned if the new WhereTerm could not be added due to a memory
+** allocation error.  The memory allocation failure will be recorded in
+** the db->mallocFailed flag so that higher-level functions can detect it.
+**
+** This routine will increase the size of the pWC->a[] array as necessary.
+**
+** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
+** for freeing the expression p is assumed by the WhereClause object pWC.
+** This is true even if this routine fails to allocate a new WhereTerm.
+**
+** WARNING:  This routine might reallocate the space used to store
+** WhereTerms.  All pointers to WhereTerms should be invalidated after
+** calling this routine.  Such pointers may be reinitialized by referencing
+** the pWC->a[] array.
+*/
+static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
+  WhereTerm *pTerm;
+  int idx;
+  testcase( wtFlags & TERM_VIRTUAL );
+  if( pWC->nTerm>=pWC->nSlot ){
+    WhereTerm *pOld = pWC->a;
+    sqlite3 *db = pWC->pWInfo->pParse->db;
+    pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
+    if( pWC->a==0 ){
+      if( wtFlags & TERM_DYNAMIC ){
+        sqlite3ExprDelete(db, p);
+      }
+      pWC->a = pOld;
+      return 0;
+    }
+    memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
+    if( pOld!=pWC->aStatic ){
+      sqlite3DbFree(db, pOld);
+    }
+    pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
+    memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm));
+  }
+  pTerm = &pWC->a[idx = pWC->nTerm++];
+  if( p && ExprHasProperty(p, EP_Unlikely) ){
+    pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
+  }else{
+    pTerm->truthProb = 1;
+  }
+  pTerm->pExpr = sqlite3ExprSkipCollate(p);
+  pTerm->wtFlags = wtFlags;
+  pTerm->pWC = pWC;
+  pTerm->iParent = -1;
+  return idx;
+}
+
+/*
+** Return TRUE if the given operator is one of the operators that is
+** allowed for an indexable WHERE clause term.  The allowed operators are
+** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
+*/
+static int allowedOp(int op){
+  assert( TK_GT>TK_EQ && TK_GT<TK_GE );
+  assert( TK_LT>TK_EQ && TK_LT<TK_GE );
+  assert( TK_LE>TK_EQ && TK_LE<TK_GE );
+  assert( TK_GE==TK_EQ+4 );
+  return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;
+}
+
+/*
+** Commute a comparison operator.  Expressions of the form "X op Y"
+** are converted into "Y op X".
+**
+** If left/right precedence rules come into play when determining the
+** collating sequence, then COLLATE operators are adjusted to ensure
+** that the collating sequence does not change.  For example:
+** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
+** the left hand side of a comparison overrides any collation sequence 
+** attached to the right. For the same reason the EP_Collate flag
+** is not commuted.
+*/
+static void exprCommute(Parse *pParse, Expr *pExpr){
+  u16 expRight = (pExpr->pRight->flags & EP_Collate);
+  u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
+  assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
+  if( expRight==expLeft ){
+    /* Either X and Y both have COLLATE operator or neither do */
+    if( expRight ){
+      /* Both X and Y have COLLATE operators.  Make sure X is always
+      ** used by clearing the EP_Collate flag from Y. */
+      pExpr->pRight->flags &= ~EP_Collate;
+    }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){
+      /* Neither X nor Y have COLLATE operators, but X has a non-default
+      ** collating sequence.  So add the EP_Collate marker on X to cause
+      ** it to be searched first. */
+      pExpr->pLeft->flags |= EP_Collate;
+    }
+  }
+  SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
+  if( pExpr->op>=TK_GT ){
+    assert( TK_LT==TK_GT+2 );
+    assert( TK_GE==TK_LE+2 );
+    assert( TK_GT>TK_EQ );
+    assert( TK_GT<TK_LE );
+    assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
+    pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
+  }
+}
+
+/*
+** Translate from TK_xx operator to WO_xx bitmask.
+*/
+static u16 operatorMask(int op){
+  u16 c;
+  assert( allowedOp(op) );
+  if( op==TK_IN ){
+    c = WO_IN;
+  }else if( op==TK_ISNULL ){
+    c = WO_ISNULL;
+  }else if( op==TK_IS ){
+    c = WO_IS;
+  }else{
+    assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
+    c = (u16)(WO_EQ<<(op-TK_EQ));
+  }
+  assert( op!=TK_ISNULL || c==WO_ISNULL );
+  assert( op!=TK_IN || c==WO_IN );
+  assert( op!=TK_EQ || c==WO_EQ );
+  assert( op!=TK_LT || c==WO_LT );
+  assert( op!=TK_LE || c==WO_LE );
+  assert( op!=TK_GT || c==WO_GT );
+  assert( op!=TK_GE || c==WO_GE );
+  assert( op!=TK_IS || c==WO_IS );
+  return c;
+}
+
+
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
+/*
+** Check to see if the given expression is a LIKE or GLOB operator that
+** can be optimized using inequality constraints.  Return TRUE if it is
+** so and false if not.
+**
+** In order for the operator to be optimizible, the RHS must be a string
+** literal that does not begin with a wildcard.  The LHS must be a column
+** that may only be NULL, a string, or a BLOB, never a number. (This means
+** that virtual tables cannot participate in the LIKE optimization.)  The
+** collating sequence for the column on the LHS must be appropriate for
+** the operator.
+*/
+static int isLikeOrGlob(
+  Parse *pParse,    /* Parsing and code generating context */
+  Expr *pExpr,      /* Test this expression */
+  Expr **ppPrefix,  /* Pointer to TK_STRING expression with pattern prefix */
+  int *pisComplete, /* True if the only wildcard is % in the last character */
+  int *pnoCase      /* True if uppercase is equivalent to lowercase */
+){
+  const char *z = 0;         /* String on RHS of LIKE operator */
+  Expr *pRight, *pLeft;      /* Right and left size of LIKE operator */
+  ExprList *pList;           /* List of operands to the LIKE operator */
+  int c;                     /* One character in z[] */
+  int cnt;                   /* Number of non-wildcard prefix characters */
+  char wc[3];                /* Wildcard characters */
+  sqlite3 *db = pParse->db;  /* Database connection */
+  sqlite3_value *pVal = 0;
+  int op;                    /* Opcode of pRight */
+
+  if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
+    return 0;
+  }
+#ifdef SQLITE_EBCDIC
+  if( *pnoCase ) return 0;
+#endif
+  pList = pExpr->x.pList;
+  pLeft = pList->a[1].pExpr;
+  if( pLeft->op!=TK_COLUMN 
+   || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT 
+   || IsVirtual(pLeft->pTab)  /* Value might be numeric */
+  ){
+    /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must
+    ** be the name of an indexed column with TEXT affinity. */
+    return 0;
+  }
+  assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */
+
+  pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
+  op = pRight->op;
+  if( op==TK_VARIABLE ){
+    Vdbe *pReprepare = pParse->pReprepare;
+    int iCol = pRight->iColumn;
+    pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);
+    if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
+      z = (char *)sqlite3_value_text(pVal);
+    }
+    sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);
+    assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
+  }else if( op==TK_STRING ){
+    z = pRight->u.zToken;
+  }
+  if( z ){
+    cnt = 0;
+    while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
+      cnt++;
+    }
+    if( cnt!=0 && 255!=(u8)z[cnt-1] ){
+      Expr *pPrefix;
+      *pisComplete = c==wc[0] && z[cnt+1]==0;
+      pPrefix = sqlite3Expr(db, TK_STRING, z);
+      if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
+      *ppPrefix = pPrefix;
+      if( op==TK_VARIABLE ){
+        Vdbe *v = pParse->pVdbe;
+        sqlite3VdbeSetVarmask(v, pRight->iColumn);
+        if( *pisComplete && pRight->u.zToken[1] ){
+          /* If the rhs of the LIKE expression is a variable, and the current
+          ** value of the variable means there is no need to invoke the LIKE
+          ** function, then no OP_Variable will be added to the program.
+          ** This causes problems for the sqlite3_bind_parameter_name()
+          ** API. To work around them, add a dummy OP_Variable here.
+          */ 
+          int r1 = sqlite3GetTempReg(pParse);
+          sqlite3ExprCodeTarget(pParse, pRight, r1);
+          sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
+          sqlite3ReleaseTempReg(pParse, r1);
+        }
+      }
+    }else{
+      z = 0;
+    }
+  }
+
+  sqlite3ValueFree(pVal);
+  return (z!=0);
+}
+#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
+
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Check to see if the given expression is of the form
+**
+**         column OP expr
+**
+** where OP is one of MATCH, GLOB, LIKE or REGEXP and "column" is a 
+** column of a virtual table.
+**
+** If it is then return TRUE.  If not, return FALSE.
+*/
+static int isMatchOfColumn(
+  Expr *pExpr,                    /* Test this expression */
+  unsigned char *peOp2            /* OUT: 0 for MATCH, or else an op2 value */
+){
+  struct Op2 {
+    const char *zOp;
+    unsigned char eOp2;
+  } aOp[] = {
+    { "match",  SQLITE_INDEX_CONSTRAINT_MATCH },
+    { "glob",   SQLITE_INDEX_CONSTRAINT_GLOB },
+    { "like",   SQLITE_INDEX_CONSTRAINT_LIKE },
+    { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }
+  };
+  ExprList *pList;
+  Expr *pCol;                     /* Column reference */
+  int i;
+
+  if( pExpr->op!=TK_FUNCTION ){
+    return 0;
+  }
+  pList = pExpr->x.pList;
+  if( pList==0 || pList->nExpr!=2 ){
+    return 0;
+  }
+  pCol = pList->a[1].pExpr;
+  if( pCol->op!=TK_COLUMN || !IsVirtual(pCol->pTab) ){
+    return 0;
+  }
+  for(i=0; i<ArraySize(aOp); i++){
+    if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
+      *peOp2 = aOp[i].eOp2;
+      return 1;
+    }
+  }
+  return 0;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** If the pBase expression originated in the ON or USING clause of
+** a join, then transfer the appropriate markings over to derived.
+*/
+static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
+  if( pDerived ){
+    pDerived->flags |= pBase->flags & EP_FromJoin;
+    pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  }
+}
+
+/*
+** Mark term iChild as being a child of term iParent
+*/
+static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
+  pWC->a[iChild].iParent = iParent;
+  pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
+  pWC->a[iParent].nChild++;
+}
+
+/*
+** Return the N-th AND-connected subterm of pTerm.  Or if pTerm is not
+** a conjunction, then return just pTerm when N==0.  If N is exceeds
+** the number of available subterms, return NULL.
+*/
+static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){
+  if( pTerm->eOperator!=WO_AND ){
+    return N==0 ? pTerm : 0;
+  }
+  if( N<pTerm->u.pAndInfo->wc.nTerm ){
+    return &pTerm->u.pAndInfo->wc.a[N];
+  }
+  return 0;
+}
+
+/*
+** Subterms pOne and pTwo are contained within WHERE clause pWC.  The
+** two subterms are in disjunction - they are OR-ed together.
+**
+** If these two terms are both of the form:  "A op B" with the same
+** A and B values but different operators and if the operators are
+** compatible (if one is = and the other is <, for example) then
+** add a new virtual AND term to pWC that is the combination of the
+** two.
+**
+** Some examples:
+**
+**    x<y OR x=y    -->     x<=y
+**    x=y OR x=y    -->     x=y
+**    x<=y OR x<y   -->     x<=y
+**
+** The following is NOT generated:
+**
+**    x<y OR x>y    -->     x!=y     
+*/
+static void whereCombineDisjuncts(
+  SrcList *pSrc,         /* the FROM clause */
+  WhereClause *pWC,      /* The complete WHERE clause */
+  WhereTerm *pOne,       /* First disjunct */
+  WhereTerm *pTwo        /* Second disjunct */
+){
+  u16 eOp = pOne->eOperator | pTwo->eOperator;
+  sqlite3 *db;           /* Database connection (for malloc) */
+  Expr *pNew;            /* New virtual expression */
+  int op;                /* Operator for the combined expression */
+  int idxNew;            /* Index in pWC of the next virtual term */
+
+  if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
+  if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
+   && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
+  assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
+  assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
+  if( sqlite3ExprCompare(pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
+  if( sqlite3ExprCompare(pOne->pExpr->pRight, pTwo->pExpr->pRight, -1) )return;
+  /* If we reach this point, it means the two subterms can be combined */
+  if( (eOp & (eOp-1))!=0 ){
+    if( eOp & (WO_LT|WO_LE) ){
+      eOp = WO_LE;
+    }else{
+      assert( eOp & (WO_GT|WO_GE) );
+      eOp = WO_GE;
+    }
+  }
+  db = pWC->pWInfo->pParse->db;
+  pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
+  if( pNew==0 ) return;
+  for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }
+  pNew->op = op;
+  idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+  exprAnalyze(pSrc, pWC, idxNew);
+}
+
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
+/*
+** Analyze a term that consists of two or more OR-connected
+** subterms.  So in:
+**
+**     ... WHERE  (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
+**                          ^^^^^^^^^^^^^^^^^^^^
+**
+** This routine analyzes terms such as the middle term in the above example.
+** A WhereOrTerm object is computed and attached to the term under
+** analysis, regardless of the outcome of the analysis.  Hence:
+**
+**     WhereTerm.wtFlags   |=  TERM_ORINFO
+**     WhereTerm.u.pOrInfo  =  a dynamically allocated WhereOrTerm object
+**
+** The term being analyzed must have two or more of OR-connected subterms.
+** A single subterm might be a set of AND-connected sub-subterms.
+** Examples of terms under analysis:
+**
+**     (A)     t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5
+**     (B)     x=expr1 OR expr2=x OR x=expr3
+**     (C)     t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
+**     (D)     x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
+**     (E)     (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
+**     (F)     x>A OR (x=A AND y>=B)
+**
+** CASE 1:
+**
+** If all subterms are of the form T.C=expr for some single column of C and
+** a single table T (as shown in example B above) then create a new virtual
+** term that is an equivalent IN expression.  In other words, if the term
+** being analyzed is:
+**
+**      x = expr1  OR  expr2 = x  OR  x = expr3
+**
+** then create a new virtual term like this:
+**
+**      x IN (expr1,expr2,expr3)
+**
+** CASE 2:
+**
+** If there are exactly two disjuncts and one side has x>A and the other side
+** has x=A (for the same x and A) then add a new virtual conjunct term to the
+** WHERE clause of the form "x>=A".  Example:
+**
+**      x>A OR (x=A AND y>B)    adds:    x>=A
+**
+** The added conjunct can sometimes be helpful in query planning.
+**
+** CASE 3:
+**
+** If all subterms are indexable by a single table T, then set
+**
+**     WhereTerm.eOperator              =  WO_OR
+**     WhereTerm.u.pOrInfo->indexable  |=  the cursor number for table T
+**
+** A subterm is "indexable" if it is of the form
+** "T.C <op> <expr>" where C is any column of table T and 
+** <op> is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
+** A subterm is also indexable if it is an AND of two or more
+** subsubterms at least one of which is indexable.  Indexable AND 
+** subterms have their eOperator set to WO_AND and they have
+** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
+**
+** From another point of view, "indexable" means that the subterm could
+** potentially be used with an index if an appropriate index exists.
+** This analysis does not consider whether or not the index exists; that
+** is decided elsewhere.  This analysis only looks at whether subterms
+** appropriate for indexing exist.
+**
+** All examples A through E above satisfy case 3.  But if a term
+** also satisfies case 1 (such as B) we know that the optimizer will
+** always prefer case 1, so in that case we pretend that case 3 is not
+** satisfied.
+**
+** It might be the case that multiple tables are indexable.  For example,
+** (E) above is indexable on tables P, Q, and R.
+**
+** Terms that satisfy case 3 are candidates for lookup by using
+** separate indices to find rowids for each subterm and composing
+** the union of all rowids using a RowSet object.  This is similar
+** to "bitmap indices" in other database engines.
+**
+** OTHERWISE:
+**
+** If none of cases 1, 2, or 3 apply, then leave the eOperator set to
+** zero.  This term is not useful for search.
+*/
+static void exprAnalyzeOrTerm(
+  SrcList *pSrc,            /* the FROM clause */
+  WhereClause *pWC,         /* the complete WHERE clause */
+  int idxTerm               /* Index of the OR-term to be analyzed */
+){
+  WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */
+  Parse *pParse = pWInfo->pParse;         /* Parser context */
+  sqlite3 *db = pParse->db;               /* Database connection */
+  WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */
+  Expr *pExpr = pTerm->pExpr;             /* The expression of the term */
+  int i;                                  /* Loop counters */
+  WhereClause *pOrWc;       /* Breakup of pTerm into subterms */
+  WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */
+  WhereOrInfo *pOrInfo;     /* Additional information associated with pTerm */
+  Bitmask chngToIN;         /* Tables that might satisfy case 1 */
+  Bitmask indexable;        /* Tables that are indexable, satisfying case 2 */
+
+  /*
+  ** Break the OR clause into its separate subterms.  The subterms are
+  ** stored in a WhereClause structure containing within the WhereOrInfo
+  ** object that is attached to the original OR clause term.
+  */
+  assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );
+  assert( pExpr->op==TK_OR );
+  pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));
+  if( pOrInfo==0 ) return;
+  pTerm->wtFlags |= TERM_ORINFO;
+  pOrWc = &pOrInfo->wc;
+  sqlite3WhereClauseInit(pOrWc, pWInfo);
+  sqlite3WhereSplit(pOrWc, pExpr, TK_OR);
+  sqlite3WhereExprAnalyze(pSrc, pOrWc);
+  if( db->mallocFailed ) return;
+  assert( pOrWc->nTerm>=2 );
+
+  /*
+  ** Compute the set of tables that might satisfy cases 1 or 3.
+  */
+  indexable = ~(Bitmask)0;
+  chngToIN = ~(Bitmask)0;
+  for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
+    if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
+      WhereAndInfo *pAndInfo;
+      assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
+      chngToIN = 0;
+      pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
+      if( pAndInfo ){
+        WhereClause *pAndWC;
+        WhereTerm *pAndTerm;
+        int j;
+        Bitmask b = 0;
+        pOrTerm->u.pAndInfo = pAndInfo;
+        pOrTerm->wtFlags |= TERM_ANDINFO;
+        pOrTerm->eOperator = WO_AND;
+        pAndWC = &pAndInfo->wc;
+        sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
+        sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
+        sqlite3WhereExprAnalyze(pSrc, pAndWC);
+        pAndWC->pOuter = pWC;
+        testcase( db->mallocFailed );
+        if( !db->mallocFailed ){
+          for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
+            assert( pAndTerm->pExpr );
+            if( allowedOp(pAndTerm->pExpr->op) ){
+              b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
+            }
+          }
+        }
+        indexable &= b;
+      }
+    }else if( pOrTerm->wtFlags & TERM_COPIED ){
+      /* Skip this term for now.  We revisit it when we process the
+      ** corresponding TERM_VIRTUAL term */
+    }else{
+      Bitmask b;
+      b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
+      if( pOrTerm->wtFlags & TERM_VIRTUAL ){
+        WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
+        b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
+      }
+      indexable &= b;
+      if( (pOrTerm->eOperator & WO_EQ)==0 ){
+        chngToIN = 0;
+      }else{
+        chngToIN &= b;
+      }
+    }
+  }
+
+  /*
+  ** Record the set of tables that satisfy case 3.  The set might be
+  ** empty.
+  */
+  pOrInfo->indexable = indexable;
+  pTerm->eOperator = indexable==0 ? 0 : WO_OR;
+
+  /* For a two-way OR, attempt to implementation case 2.
+  */
+  if( indexable && pOrWc->nTerm==2 ){
+    int iOne = 0;
+    WhereTerm *pOne;
+    while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){
+      int iTwo = 0;
+      WhereTerm *pTwo;
+      while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){
+        whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);
+      }
+    }
+  }
+
+  /*
+  ** chngToIN holds a set of tables that *might* satisfy case 1.  But
+  ** we have to do some additional checking to see if case 1 really
+  ** is satisfied.
+  **
+  ** chngToIN will hold either 0, 1, or 2 bits.  The 0-bit case means
+  ** that there is no possibility of transforming the OR clause into an
+  ** IN operator because one or more terms in the OR clause contain
+  ** something other than == on a column in the single table.  The 1-bit
+  ** case means that every term of the OR clause is of the form
+  ** "table.column=expr" for some single table.  The one bit that is set
+  ** will correspond to the common table.  We still need to check to make
+  ** sure the same column is used on all terms.  The 2-bit case is when
+  ** the all terms are of the form "table1.column=table2.column".  It
+  ** might be possible to form an IN operator with either table1.column
+  ** or table2.column as the LHS if either is common to every term of
+  ** the OR clause.
+  **
+  ** Note that terms of the form "table.column1=table.column2" (the
+  ** same table on both sizes of the ==) cannot be optimized.
+  */
+  if( chngToIN ){
+    int okToChngToIN = 0;     /* True if the conversion to IN is valid */
+    int iColumn = -1;         /* Column index on lhs of IN operator */
+    int iCursor = -1;         /* Table cursor common to all terms */
+    int j = 0;                /* Loop counter */
+
+    /* Search for a table and column that appears on one side or the
+    ** other of the == operator in every subterm.  That table and column
+    ** will be recorded in iCursor and iColumn.  There might not be any
+    ** such table and column.  Set okToChngToIN if an appropriate table
+    ** and column is found but leave okToChngToIN false if not found.
+    */
+    for(j=0; j<2 && !okToChngToIN; j++){
+      pOrTerm = pOrWc->a;
+      for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
+        assert( pOrTerm->eOperator & WO_EQ );
+        pOrTerm->wtFlags &= ~TERM_OR_OK;
+        if( pOrTerm->leftCursor==iCursor ){
+          /* This is the 2-bit case and we are on the second iteration and
+          ** current term is from the first iteration.  So skip this term. */
+          assert( j==1 );
+          continue;
+        }
+        if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,
+                                            pOrTerm->leftCursor))==0 ){
+          /* This term must be of the form t1.a==t2.b where t2 is in the
+          ** chngToIN set but t1 is not.  This term will be either preceded
+          ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
+          ** and use its inversion. */
+          testcase( pOrTerm->wtFlags & TERM_COPIED );
+          testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
+          assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
+          continue;
+        }
+        iColumn = pOrTerm->u.leftColumn;
+        iCursor = pOrTerm->leftCursor;
+        break;
+      }
+      if( i<0 ){
+        /* No candidate table+column was found.  This can only occur
+        ** on the second iteration */
+        assert( j==1 );
+        assert( IsPowerOfTwo(chngToIN) );
+        assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
+        break;
+      }
+      testcase( j==1 );
+
+      /* We have found a candidate table and column.  Check to see if that
+      ** table and column is common to every term in the OR clause */
+      okToChngToIN = 1;
+      for(; i>=0 && okToChngToIN; i--, pOrTerm++){
+        assert( pOrTerm->eOperator & WO_EQ );
+        if( pOrTerm->leftCursor!=iCursor ){
+          pOrTerm->wtFlags &= ~TERM_OR_OK;
+        }else if( pOrTerm->u.leftColumn!=iColumn ){
+          okToChngToIN = 0;
+        }else{
+          int affLeft, affRight;
+          /* If the right-hand side is also a column, then the affinities
+          ** of both right and left sides must be such that no type
+          ** conversions are required on the right.  (Ticket #2249)
+          */
+          affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);
+          affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
+          if( affRight!=0 && affRight!=affLeft ){
+            okToChngToIN = 0;
+          }else{
+            pOrTerm->wtFlags |= TERM_OR_OK;
+          }
+        }
+      }
+    }
+
+    /* At this point, okToChngToIN is true if original pTerm satisfies
+    ** case 1.  In that case, construct a new virtual term that is 
+    ** pTerm converted into an IN operator.
+    */
+    if( okToChngToIN ){
+      Expr *pDup;            /* A transient duplicate expression */
+      ExprList *pList = 0;   /* The RHS of the IN operator */
+      Expr *pLeft = 0;       /* The LHS of the IN operator */
+      Expr *pNew;            /* The complete IN operator */
+
+      for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
+        if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
+        assert( pOrTerm->eOperator & WO_EQ );
+        assert( pOrTerm->leftCursor==iCursor );
+        assert( pOrTerm->u.leftColumn==iColumn );
+        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
+        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
+        pLeft = pOrTerm->pExpr->pLeft;
+      }
+      assert( pLeft!=0 );
+      pDup = sqlite3ExprDup(db, pLeft, 0);
+      pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0, 0);
+      if( pNew ){
+        int idxNew;
+        transferJoinMarkings(pNew, pExpr);
+        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
+        pNew->x.pList = pList;
+        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
+        testcase( idxNew==0 );
+        exprAnalyze(pSrc, pWC, idxNew);
+        pTerm = &pWC->a[idxTerm];
+        markTermAsChild(pWC, idxNew, idxTerm);
+      }else{
+        sqlite3ExprListDelete(db, pList);
+      }
+      pTerm->eOperator = WO_NOOP;  /* case 1 trumps case 3 */
+    }
+  }
+}
+#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
+
+/*
+** We already know that pExpr is a binary operator where both operands are
+** column references.  This routine checks to see if pExpr is an equivalence
+** relation:
+**   1.  The SQLITE_Transitive optimization must be enabled
+**   2.  Must be either an == or an IS operator
+**   3.  Not originating in the ON clause of an OUTER JOIN
+**   4.  The affinities of A and B must be compatible
+**   5a. Both operands use the same collating sequence OR
+**   5b. The overall collating sequence is BINARY
+** If this routine returns TRUE, that means that the RHS can be substituted
+** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
+** This is an optimization.  No harm comes from returning 0.  But if 1 is
+** returned when it should not be, then incorrect answers might result.
+*/
+static int termIsEquivalence(Parse *pParse, Expr *pExpr){
+  char aff1, aff2;
+  CollSeq *pColl;
+  const char *zColl1, *zColl2;
+  if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
+  if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
+  if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
+  aff1 = sqlite3ExprAffinity(pExpr->pLeft);
+  aff2 = sqlite3ExprAffinity(pExpr->pRight);
+  if( aff1!=aff2
+   && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
+  ){
+    return 0;
+  }
+  pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
+  if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+  /* Since pLeft and pRight are both a column references, their collating
+  ** sequence should always be defined. */
+  zColl1 = ALWAYS(pColl) ? pColl->zName : 0;
+  pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
+  zColl2 = ALWAYS(pColl) ? pColl->zName : 0;
+  return sqlite3StrICmp(zColl1, zColl2)==0;
+}
+
+/*
+** Recursively walk the expressions of a SELECT statement and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
+*/
+static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){
+  Bitmask mask = 0;
+  while( pS ){
+    SrcList *pSrc = pS->pSrc;
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
+    mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
+    mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
+    if( ALWAYS(pSrc!=0) ){
+      int i;
+      for(i=0; i<pSrc->nSrc; i++){
+        mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);
+        mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
+      }
+    }
+    pS = pS->pPrior;
+  }
+  return mask;
+}
+
+/*
+** Expression pExpr is one operand of a comparison operator that might
+** be useful for indexing.  This routine checks to see if pExpr appears
+** in any index.  Return TRUE (1) if pExpr is an indexed term and return
+** FALSE (0) if not.  If TRUE is returned, also set *piCur to the cursor
+** number of the table that is indexed and *piColumn to the column number
+** of the column that is indexed, or -2 if an expression is being indexed.
+**
+** If pExpr is a TK_COLUMN column reference, then this routine always returns
+** true even if that particular column is not indexed, because the column
+** might be added to an automatic index later.
+*/
+static int exprMightBeIndexed(
+  SrcList *pFrom,        /* The FROM clause */
+  Bitmask mPrereq,       /* Bitmask of FROM clause terms referenced by pExpr */
+  Expr *pExpr,           /* An operand of a comparison operator */
+  int *piCur,            /* Write the referenced table cursor number here */
+  int *piColumn          /* Write the referenced table column number here */
+){
+  Index *pIdx;
+  int i;
+  int iCur;
+  if( pExpr->op==TK_COLUMN ){
+    *piCur = pExpr->iTable;
+    *piColumn = pExpr->iColumn;
+    return 1;
+  }
+  if( mPrereq==0 ) return 0;                 /* No table references */
+  if( (mPrereq&(mPrereq-1))!=0 ) return 0;   /* Refs more than one table */
+  for(i=0; mPrereq>1; i++, mPrereq>>=1){}
+  iCur = pFrom->a[i].iCursor;
+  for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    if( pIdx->aColExpr==0 ) continue;
+    for(i=0; i<pIdx->nKeyCol; i++){
+      if( pIdx->aiColumn[i]!=(-2) ) continue;
+      if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
+        *piCur = iCur;
+        *piColumn = -2;
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** The input to this routine is an WhereTerm structure with only the
+** "pExpr" field filled in.  The job of this routine is to analyze the
+** subexpression and populate all the other fields of the WhereTerm
+** structure.
+**
+** If the expression is of the form "<expr> <op> X" it gets commuted
+** to the standard form of "X <op> <expr>".
+**
+** If the expression is of the form "X <op> Y" where both X and Y are
+** columns, then the original expression is unchanged and a new virtual
+** term of the form "Y <op> X" is added to the WHERE clause and
+** analyzed separately.  The original term is marked with TERM_COPIED
+** and the new term is marked with TERM_DYNAMIC (because it's pExpr
+** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it
+** is a commuted copy of a prior term.)  The original term has nChild=1
+** and the copy has idxParent set to the index of the original term.
+*/
+static void exprAnalyze(
+  SrcList *pSrc,            /* the FROM clause */
+  WhereClause *pWC,         /* the WHERE clause */
+  int idxTerm               /* Index of the term to be analyzed */
+){
+  WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
+  WhereTerm *pTerm;                /* The term to be analyzed */
+  WhereMaskSet *pMaskSet;          /* Set of table index masks */
+  Expr *pExpr;                     /* The expression to be analyzed */
+  Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */
+  Bitmask prereqAll;               /* Prerequesites of pExpr */
+  Bitmask extraRight = 0;          /* Extra dependencies on LEFT JOIN */
+  Expr *pStr1 = 0;                 /* RHS of LIKE/GLOB operator */
+  int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
+  int noCase = 0;                  /* uppercase equivalent to lowercase */
+  int op;                          /* Top-level operator.  pExpr->op */
+  Parse *pParse = pWInfo->pParse;  /* Parsing context */
+  sqlite3 *db = pParse->db;        /* Database connection */
+  unsigned char eOp2;              /* op2 value for LIKE/REGEXP/GLOB */
+
+  if( db->mallocFailed ){
+    return;
+  }
+  pTerm = &pWC->a[idxTerm];
+  pMaskSet = &pWInfo->sMaskSet;
+  pExpr = pTerm->pExpr;
+  assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
+  prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
+  op = pExpr->op;
+  if( op==TK_IN ){
+    assert( pExpr->pRight==0 );
+    if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+      pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
+    }else{
+      pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
+    }
+  }else if( op==TK_ISNULL ){
+    pTerm->prereqRight = 0;
+  }else{
+    pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
+  }
+  prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr);
+  if( ExprHasProperty(pExpr, EP_FromJoin) ){
+    Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
+    prereqAll |= x;
+    extraRight = x-1;  /* ON clause terms may not be used with an index
+                       ** on left table of a LEFT JOIN.  Ticket #3015 */
+  }
+  pTerm->prereqAll = prereqAll;
+  pTerm->leftCursor = -1;
+  pTerm->iParent = -1;
+  pTerm->eOperator = 0;
+  if( allowedOp(op) ){
+    int iCur, iColumn;
+    Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
+    Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
+    u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
+    if( exprMightBeIndexed(pSrc, prereqLeft, pLeft, &iCur, &iColumn) ){
+      pTerm->leftCursor = iCur;
+      pTerm->u.leftColumn = iColumn;
+      pTerm->eOperator = operatorMask(op) & opMask;
+    }
+    if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
+    if( pRight 
+     && exprMightBeIndexed(pSrc, pTerm->prereqRight, pRight, &iCur, &iColumn)
+    ){
+      WhereTerm *pNew;
+      Expr *pDup;
+      u16 eExtraOp = 0;        /* Extra bits for pNew->eOperator */
+      if( pTerm->leftCursor>=0 ){
+        int idxNew;
+        pDup = sqlite3ExprDup(db, pExpr, 0);
+        if( db->mallocFailed ){
+          sqlite3ExprDelete(db, pDup);
+          return;
+        }
+        idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
+        if( idxNew==0 ) return;
+        pNew = &pWC->a[idxNew];
+        markTermAsChild(pWC, idxNew, idxTerm);
+        if( op==TK_IS ) pNew->wtFlags |= TERM_IS;
+        pTerm = &pWC->a[idxTerm];
+        pTerm->wtFlags |= TERM_COPIED;
+
+        if( termIsEquivalence(pParse, pDup) ){
+          pTerm->eOperator |= WO_EQUIV;
+          eExtraOp = WO_EQUIV;
+        }
+      }else{
+        pDup = pExpr;
+        pNew = pTerm;
+      }
+      exprCommute(pParse, pDup);
+      pNew->leftCursor = iCur;
+      pNew->u.leftColumn = iColumn;
+      testcase( (prereqLeft | extraRight) != prereqLeft );
+      pNew->prereqRight = prereqLeft | extraRight;
+      pNew->prereqAll = prereqAll;
+      pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
+    }
+  }
+
+#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
+  /* If a term is the BETWEEN operator, create two new virtual terms
+  ** that define the range that the BETWEEN implements.  For example:
+  **
+  **      a BETWEEN b AND c
+  **
+  ** is converted into:
+  **
+  **      (a BETWEEN b AND c) AND (a>=b) AND (a<=c)
+  **
+  ** The two new terms are added onto the end of the WhereClause object.
+  ** The new terms are "dynamic" and are children of the original BETWEEN
+  ** term.  That means that if the BETWEEN term is coded, the children are
+  ** skipped.  Or, if the children are satisfied by an index, the original
+  ** BETWEEN term is skipped.
+  */
+  else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){
+    ExprList *pList = pExpr->x.pList;
+    int i;
+    static const u8 ops[] = {TK_GE, TK_LE};
+    assert( pList!=0 );
+    assert( pList->nExpr==2 );
+    for(i=0; i<2; i++){
+      Expr *pNewExpr;
+      int idxNew;
+      pNewExpr = sqlite3PExpr(pParse, ops[i], 
+                             sqlite3ExprDup(db, pExpr->pLeft, 0),
+                             sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
+      transferJoinMarkings(pNewExpr, pExpr);
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      testcase( idxNew==0 );
+      exprAnalyze(pSrc, pWC, idxNew);
+      pTerm = &pWC->a[idxTerm];
+      markTermAsChild(pWC, idxNew, idxTerm);
+    }
+  }
+#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
+
+#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
+  /* Analyze a term that is composed of two or more subterms connected by
+  ** an OR operator.
+  */
+  else if( pExpr->op==TK_OR ){
+    assert( pWC->op==TK_AND );
+    exprAnalyzeOrTerm(pSrc, pWC, idxTerm);
+    pTerm = &pWC->a[idxTerm];
+  }
+#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
+
+#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
+  /* Add constraints to reduce the search space on a LIKE or GLOB
+  ** operator.
+  **
+  ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints
+  **
+  **          x>='ABC' AND x<'abd' AND x LIKE 'aBc%'
+  **
+  ** The last character of the prefix "abc" is incremented to form the
+  ** termination condition "abd".  If case is not significant (the default
+  ** for LIKE) then the lower-bound is made all uppercase and the upper-
+  ** bound is made all lowercase so that the bounds also work when comparing
+  ** BLOBs.
+  */
+  if( pWC->op==TK_AND 
+   && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
+  ){
+    Expr *pLeft;       /* LHS of LIKE/GLOB operator */
+    Expr *pStr2;       /* Copy of pStr1 - RHS of LIKE/GLOB operator */
+    Expr *pNewExpr1;
+    Expr *pNewExpr2;
+    int idxNew1;
+    int idxNew2;
+    const char *zCollSeqName;     /* Name of collating sequence */
+    const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;
+
+    pLeft = pExpr->x.pList->a[1].pExpr;
+    pStr2 = sqlite3ExprDup(db, pStr1, 0);
+
+    /* Convert the lower bound to upper-case and the upper bound to
+    ** lower-case (upper-case is less than lower-case in ASCII) so that
+    ** the range constraints also work for BLOBs
+    */
+    if( noCase && !pParse->db->mallocFailed ){
+      int i;
+      char c;
+      pTerm->wtFlags |= TERM_LIKE;
+      for(i=0; (c = pStr1->u.zToken[i])!=0; i++){
+        pStr1->u.zToken[i] = sqlite3Toupper(c);
+        pStr2->u.zToken[i] = sqlite3Tolower(c);
+      }
+    }
+
+    if( !db->mallocFailed ){
+      u8 c, *pC;       /* Last character before the first wildcard */
+      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
+      c = *pC;
+      if( noCase ){
+        /* The point is to increment the last character before the first
+        ** wildcard.  But if we increment '@', that will push it into the
+        ** alphabetic range where case conversions will mess up the 
+        ** inequality.  To avoid this, make sure to also run the full
+        ** LIKE on all candidate expressions by clearing the isComplete flag
+        */
+        if( c=='A'-1 ) isComplete = 0;
+        c = sqlite3UpperToLower[c];
+      }
+      *pC = c + 1;
+    }
+    zCollSeqName = noCase ? "NOCASE" : "BINARY";
+    pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
+    pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
+           sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
+           pStr1, 0);
+    transferJoinMarkings(pNewExpr1, pExpr);
+    idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
+    testcase( idxNew1==0 );
+    exprAnalyze(pSrc, pWC, idxNew1);
+    pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
+    pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
+           sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),
+           pStr2, 0);
+    transferJoinMarkings(pNewExpr2, pExpr);
+    idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);
+    testcase( idxNew2==0 );
+    exprAnalyze(pSrc, pWC, idxNew2);
+    pTerm = &pWC->a[idxTerm];
+    if( isComplete ){
+      markTermAsChild(pWC, idxNew1, idxTerm);
+      markTermAsChild(pWC, idxNew2, idxTerm);
+    }
+  }
+#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  /* Add a WO_MATCH auxiliary term to the constraint set if the
+  ** current expression is of the form:  column MATCH expr.
+  ** This information is used by the xBestIndex methods of
+  ** virtual tables.  The native query optimizer does not attempt
+  ** to do anything with MATCH functions.
+  */
+  if( isMatchOfColumn(pExpr, &eOp2) ){
+    int idxNew;
+    Expr *pRight, *pLeft;
+    WhereTerm *pNewTerm;
+    Bitmask prereqColumn, prereqExpr;
+
+    pRight = pExpr->x.pList->a[0].pExpr;
+    pLeft = pExpr->x.pList->a[1].pExpr;
+    prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
+    prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
+    if( (prereqExpr & prereqColumn)==0 ){
+      Expr *pNewExpr;
+      pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 
+                              0, sqlite3ExprDup(db, pRight, 0), 0);
+      idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
+      testcase( idxNew==0 );
+      pNewTerm = &pWC->a[idxNew];
+      pNewTerm->prereqRight = prereqExpr;
+      pNewTerm->leftCursor = pLeft->iTable;
+      pNewTerm->u.leftColumn = pLeft->iColumn;
+      pNewTerm->eOperator = WO_MATCH;
+      pNewTerm->eMatchOp = eOp2;
+      markTermAsChild(pWC, idxNew, idxTerm);
+      pTerm = &pWC->a[idxTerm];
+      pTerm->wtFlags |= TERM_COPIED;
+      pNewTerm->prereqAll = pTerm->prereqAll;
+    }
+  }
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  /* When sqlite_stat3 histogram data is available an operator of the
+  ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
+  ** as "x>NULL" if x is not an INTEGER PRIMARY KEY.  So construct a
+  ** virtual term of that form.
+  **
+  ** Note that the virtual term must be tagged with TERM_VNULL.
+  */
+  if( pExpr->op==TK_NOTNULL
+   && pExpr->pLeft->op==TK_COLUMN
+   && pExpr->pLeft->iColumn>=0
+   && OptimizationEnabled(db, SQLITE_Stat34)
+  ){
+    Expr *pNewExpr;
+    Expr *pLeft = pExpr->pLeft;
+    int idxNew;
+    WhereTerm *pNewTerm;
+
+    pNewExpr = sqlite3PExpr(pParse, TK_GT,
+                            sqlite3ExprDup(db, pLeft, 0),
+                            sqlite3PExpr(pParse, TK_NULL, 0, 0, 0), 0);
+
+    idxNew = whereClauseInsert(pWC, pNewExpr,
+                              TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
+    if( idxNew ){
+      pNewTerm = &pWC->a[idxNew];
+      pNewTerm->prereqRight = 0;
+      pNewTerm->leftCursor = pLeft->iTable;
+      pNewTerm->u.leftColumn = pLeft->iColumn;
+      pNewTerm->eOperator = WO_GT;
+      markTermAsChild(pWC, idxNew, idxTerm);
+      pTerm = &pWC->a[idxTerm];
+      pTerm->wtFlags |= TERM_COPIED;
+      pNewTerm->prereqAll = pTerm->prereqAll;
+    }
+  }
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+  /* Prevent ON clause terms of a LEFT JOIN from being used to drive
+  ** an index for tables to the left of the join.
+  */
+  pTerm->prereqRight |= extraRight;
+}
+
+/***************************************************************************
+** Routines with file scope above.  Interface to the rest of the where.c
+** subsystem follows.
+***************************************************************************/
+
+/*
+** This routine identifies subexpressions in the WHERE clause where
+** each subexpression is separated by the AND operator or some other
+** operator specified in the op parameter.  The WhereClause structure
+** is filled with pointers to subexpressions.  For example:
+**
+**    WHERE  a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
+**           \________/     \_______________/     \________________/
+**            slot[0]            slot[1]               slot[2]
+**
+** The original WHERE clause in pExpr is unaltered.  All this routine
+** does is make slot[] entries point to substructure within pExpr.
+**
+** In the previous sentence and in the diagram, "slot[]" refers to
+** the WhereClause.a[] array.  The slot[] array grows as needed to contain
+** all terms of the WHERE clause.
+*/
+SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
+  Expr *pE2 = sqlite3ExprSkipCollate(pExpr);
+  pWC->op = op;
+  if( pE2==0 ) return;
+  if( pE2->op!=op ){
+    whereClauseInsert(pWC, pExpr, 0);
+  }else{
+    sqlite3WhereSplit(pWC, pE2->pLeft, op);
+    sqlite3WhereSplit(pWC, pE2->pRight, op);
+  }
+}
+
+/*
+** Initialize a preallocated WhereClause structure.
+*/
+SQLITE_PRIVATE void sqlite3WhereClauseInit(
+  WhereClause *pWC,        /* The WhereClause to be initialized */
+  WhereInfo *pWInfo        /* The WHERE processing context */
+){
+  pWC->pWInfo = pWInfo;
+  pWC->pOuter = 0;
+  pWC->nTerm = 0;
+  pWC->nSlot = ArraySize(pWC->aStatic);
+  pWC->a = pWC->aStatic;
+}
+
+/*
+** Deallocate a WhereClause structure.  The WhereClause structure
+** itself is not freed.  This routine is the inverse of
+** sqlite3WhereClauseInit().
+*/
+SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause *pWC){
+  int i;
+  WhereTerm *a;
+  sqlite3 *db = pWC->pWInfo->pParse->db;
+  for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
+    if( a->wtFlags & TERM_DYNAMIC ){
+      sqlite3ExprDelete(db, a->pExpr);
+    }
+    if( a->wtFlags & TERM_ORINFO ){
+      whereOrInfoDelete(db, a->u.pOrInfo);
+    }else if( a->wtFlags & TERM_ANDINFO ){
+      whereAndInfoDelete(db, a->u.pAndInfo);
+    }
+  }
+  if( pWC->a!=pWC->aStatic ){
+    sqlite3DbFree(db, pWC->a);
+  }
+}
+
+
+/*
+** These routines walk (recursively) an expression tree and generate
+** a bitmask indicating which tables are used in that expression
+** tree.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
+  Bitmask mask = 0;
+  if( p==0 ) return 0;
+  if( p->op==TK_COLUMN ){
+    mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
+    return mask;
+  }
+  mask = sqlite3WhereExprUsage(pMaskSet, p->pRight);
+  mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
+  if( ExprHasProperty(p, EP_xIsSelect) ){
+    mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
+  }else{
+    mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
+  }
+  return mask;
+}
+SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
+  int i;
+  Bitmask mask = 0;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+      mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
+    }
+  }
+  return mask;
+}
+
+
+/*
+** Call exprAnalyze on all terms in a WHERE clause.  
+**
+** Note that exprAnalyze() might add new virtual terms onto the
+** end of the WHERE clause.  We do not want to analyze these new
+** virtual terms, so start analyzing at the end and work forward
+** so that the added virtual terms are never processed.
+*/
+SQLITE_PRIVATE void sqlite3WhereExprAnalyze(
+  SrcList *pTabList,       /* the FROM clause */
+  WhereClause *pWC         /* the WHERE clause to be analyzed */
+){
+  int i;
+  for(i=pWC->nTerm-1; i>=0; i--){
+    exprAnalyze(pTabList, pWC, i);
+  }
+}
+
+/*
+** For table-valued-functions, transform the function arguments into
+** new WHERE clause terms.  
+**
+** Each function argument translates into an equality constraint against
+** a HIDDEN column in the table.
+*/
+SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(
+  Parse *pParse,                    /* Parsing context */
+  struct SrcList_item *pItem,       /* The FROM clause term to process */
+  WhereClause *pWC                  /* Xfer function arguments to here */
+){
+  Table *pTab;
+  int j, k;
+  ExprList *pArgs;
+  Expr *pColRef;
+  Expr *pTerm;
+  if( pItem->fg.isTabFunc==0 ) return;
+  pTab = pItem->pTab;
+  assert( pTab!=0 );
+  pArgs = pItem->u1.pFuncArg;
+  if( pArgs==0 ) return;
+  for(j=k=0; j<pArgs->nExpr; j++){
+    while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
+    if( k>=pTab->nCol ){
+      sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
+                      pTab->zName, j);
+      return;
+    }
+    pColRef = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
+    if( pColRef==0 ) return;
+    pColRef->iTable = pItem->iCursor;
+    pColRef->iColumn = k++;
+    pColRef->pTab = pTab;
+    pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef,
+                         sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
+    whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
+  }
+}
+
+/************** End of whereexpr.c *******************************************/
+/************** Begin file where.c *******************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This module contains C code that generates VDBE code used to process
+** the WHERE clause of SQL statements.  This module is responsible for
+** generating the code that loops through a table looking for applicable
+** rows.  Indices are selected and used to speed the search when doing
+** so is applicable.  Because this module is responsible for selecting
+** indices, you might also think of this module as the "query optimizer".
+*/
+/* #include "sqliteInt.h" */
+/* #include "whereInt.h" */
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/* Test variable that can be set to enable WHERE tracing */
+#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
+/***/ int sqlite3WhereTrace = 0;
+#endif
+
+
+/*
+** Return the estimated number of output rows from a WHERE clause
+*/
+SQLITE_PRIVATE u64 sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
+  return sqlite3LogEstToInt(pWInfo->nRowOut);
+}
+
+/*
+** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
+** WHERE clause returns outputs for DISTINCT processing.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
+  return pWInfo->eDistinct;
+}
+
+/*
+** Return TRUE if the WHERE clause returns rows in ORDER BY order.
+** Return FALSE if the output needs to be sorted.
+*/
+SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
+  return pWInfo->nOBSat;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to continue
+** immediately with the next row of a WHERE clause.
+*/
+SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
+  assert( pWInfo->iContinue!=0 );
+  return pWInfo->iContinue;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to break
+** out of a WHERE loop.
+*/
+SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
+  return pWInfo->iBreak;
+}
+
+/*
+** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to
+** operate directly on the rowis returned by a WHERE clause.  Return
+** ONEPASS_SINGLE (1) if the statement can operation directly because only
+** a single row is to be changed.  Return ONEPASS_MULTI (2) if the one-pass
+** optimization can be used on multiple 
+**
+** If the ONEPASS optimization is used (if this routine returns true)
+** then also write the indices of open cursors used by ONEPASS
+** into aiCur[0] and aiCur[1].  iaCur[0] gets the cursor of the data
+** table and iaCur[1] gets the cursor used by an auxiliary index.
+** Either value may be -1, indicating that cursor is not used.
+** Any cursors returned will have been opened for writing.
+**
+** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
+** unable to use the ONEPASS optimization.
+*/
+SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
+  memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){
+    sqlite3DebugPrintf("%s cursors: %d %d\n",
+         pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",
+         aiCur[0], aiCur[1]);
+  }
+#endif
+  return pWInfo->eOnePass;
+}
+
+/*
+** Move the content of pSrc into pDest
+*/
+static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
+  pDest->n = pSrc->n;
+  memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
+}
+
+/*
+** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
+**
+** The new entry might overwrite an existing entry, or it might be
+** appended, or it might be discarded.  Do whatever is the right thing
+** so that pSet keeps the N_OR_COST best entries seen so far.
+*/
+static int whereOrInsert(
+  WhereOrSet *pSet,      /* The WhereOrSet to be updated */
+  Bitmask prereq,        /* Prerequisites of the new entry */
+  LogEst rRun,           /* Run-cost of the new entry */
+  LogEst nOut            /* Number of outputs for the new entry */
+){
+  u16 i;
+  WhereOrCost *p;
+  for(i=pSet->n, p=pSet->a; i>0; i--, p++){
+    if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
+      goto whereOrInsert_done;
+    }
+    if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
+      return 0;
+    }
+  }
+  if( pSet->n<N_OR_COST ){
+    p = &pSet->a[pSet->n++];
+    p->nOut = nOut;
+  }else{
+    p = pSet->a;
+    for(i=1; i<pSet->n; i++){
+      if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
+    }
+    if( p->rRun<=rRun ) return 0;
+  }
+whereOrInsert_done:
+  p->prereq = prereq;
+  p->rRun = rRun;
+  if( p->nOut>nOut ) p->nOut = nOut;
+  return 1;
+}
+
+/*
+** Return the bitmask for the given cursor number.  Return 0 if
+** iCursor is not in the set.
+*/
+SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
+  int i;
+  assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
+  for(i=0; i<pMaskSet->n; i++){
+    if( pMaskSet->ix[i]==iCursor ){
+      return MASKBIT(i);
+    }
+  }
+  return 0;
+}
+
+/*
+** Create a new mask for cursor iCursor.
+**
+** There is one cursor per table in the FROM clause.  The number of
+** tables in the FROM clause is limited by a test early in the
+** sqlite3WhereBegin() routine.  So we know that the pMaskSet->ix[]
+** array will never overflow.
+*/
+static void createMask(WhereMaskSet *pMaskSet, int iCursor){
+  assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
+  pMaskSet->ix[pMaskSet->n++] = iCursor;
+}
+
+/*
+** Advance to the next WhereTerm that matches according to the criteria
+** established when the pScan object was initialized by whereScanInit().
+** Return NULL if there are no more matching WhereTerms.
+*/
+static WhereTerm *whereScanNext(WhereScan *pScan){
+  int iCur;            /* The cursor on the LHS of the term */
+  i16 iColumn;         /* The column on the LHS of the term.  -1 for IPK */
+  Expr *pX;            /* An expression being tested */
+  WhereClause *pWC;    /* Shorthand for pScan->pWC */
+  WhereTerm *pTerm;    /* The term being tested */
+  int k = pScan->k;    /* Where to start scanning */
+
+  while( pScan->iEquiv<=pScan->nEquiv ){
+    iCur = pScan->aiCur[pScan->iEquiv-1];
+    iColumn = pScan->aiColumn[pScan->iEquiv-1];
+    if( iColumn==XN_EXPR && pScan->pIdxExpr==0 ) return 0;
+    while( (pWC = pScan->pWC)!=0 ){
+      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
+        if( pTerm->leftCursor==iCur
+         && pTerm->u.leftColumn==iColumn
+         && (iColumn!=XN_EXPR
+             || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
+         && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+        ){
+          if( (pTerm->eOperator & WO_EQUIV)!=0
+           && pScan->nEquiv<ArraySize(pScan->aiCur)
+           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
+          ){
+            int j;
+            for(j=0; j<pScan->nEquiv; j++){
+              if( pScan->aiCur[j]==pX->iTable
+               && pScan->aiColumn[j]==pX->iColumn ){
+                  break;
+              }
+            }
+            if( j==pScan->nEquiv ){
+              pScan->aiCur[j] = pX->iTable;
+              pScan->aiColumn[j] = pX->iColumn;
+              pScan->nEquiv++;
+            }
+          }
+          if( (pTerm->eOperator & pScan->opMask)!=0 ){
+            /* Verify the affinity and collating sequence match */
+            if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
+              CollSeq *pColl;
+              Parse *pParse = pWC->pWInfo->pParse;
+              pX = pTerm->pExpr;
+              if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
+                continue;
+              }
+              assert(pX->pLeft);
+              pColl = sqlite3BinaryCompareCollSeq(pParse,
+                                                  pX->pLeft, pX->pRight);
+              if( pColl==0 ) pColl = pParse->db->pDfltColl;
+              if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
+                continue;
+              }
+            }
+            if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
+             && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
+             && pX->iTable==pScan->aiCur[0]
+             && pX->iColumn==pScan->aiColumn[0]
+            ){
+              testcase( pTerm->eOperator & WO_IS );
+              continue;
+            }
+            pScan->k = k+1;
+            return pTerm;
+          }
+        }
+      }
+      pScan->pWC = pScan->pWC->pOuter;
+      k = 0;
+    }
+    pScan->pWC = pScan->pOrigWC;
+    k = 0;
+    pScan->iEquiv++;
+  }
+  return 0;
+}
+
+/*
+** Initialize a WHERE clause scanner object.  Return a pointer to the
+** first match.  Return NULL if there are no matches.
+**
+** The scanner will be searching the WHERE clause pWC.  It will look
+** for terms of the form "X <op> <expr>" where X is column iColumn of table
+** iCur.  The <op> must be one of the operators described by opMask.
+**
+** If the search is for X and the WHERE clause contains terms of the
+** form X=Y then this routine might also return terms of the form
+** "Y <op> <expr>".  The number of levels of transitivity is limited,
+** but is enough to handle most commonly occurring SQL statements.
+**
+** If X is not the INTEGER PRIMARY KEY then X must be compatible with
+** index pIdx.
+*/
+static WhereTerm *whereScanInit(
+  WhereScan *pScan,       /* The WhereScan object being initialized */
+  WhereClause *pWC,       /* The WHERE clause to be scanned */
+  int iCur,               /* Cursor to scan for */
+  int iColumn,            /* Column to scan for */
+  u32 opMask,             /* Operator(s) to scan for */
+  Index *pIdx             /* Must be compatible with this index */
+){
+  int j = 0;
+
+  /* memset(pScan, 0, sizeof(*pScan)); */
+  pScan->pOrigWC = pWC;
+  pScan->pWC = pWC;
+  pScan->pIdxExpr = 0;
+  if( pIdx ){
+    j = iColumn;
+    iColumn = pIdx->aiColumn[j];
+    if( iColumn==XN_EXPR ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
+  }
+  if( pIdx && iColumn>=0 ){
+    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
+    pScan->zCollName = pIdx->azColl[j];
+  }else{
+    pScan->idxaff = 0;
+    pScan->zCollName = 0;
+  }
+  pScan->opMask = opMask;
+  pScan->k = 0;
+  pScan->aiCur[0] = iCur;
+  pScan->aiColumn[0] = iColumn;
+  pScan->nEquiv = 1;
+  pScan->iEquiv = 1;
+  return whereScanNext(pScan);
+}
+
+/*
+** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
+** where X is a reference to the iColumn of table iCur and <op> is one of
+** the WO_xx operator codes specified by the op parameter.
+** Return a pointer to the term.  Return 0 if not found.
+**
+** If pIdx!=0 then search for terms matching the iColumn-th column of pIdx
+** rather than the iColumn-th column of table iCur.
+**
+** The term returned might by Y=<expr> if there is another constraint in
+** the WHERE clause that specifies that X=Y.  Any such constraints will be
+** identified by the WO_EQUIV bit in the pTerm->eOperator field.  The
+** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
+** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
+** other equivalent values.  Hence a search for X will return <expr> if X=A1
+** and A1=A2 and A2=A3 and ... and A9=A10 and A10=<expr>.
+**
+** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
+** then try for the one with no dependencies on <expr> - in other words where
+** <expr> is a constant expression of some kind.  Only return entries of
+** the form "X <op> Y" where Y is a column in another table if no terms of
+** the form "X <op> <const-expr>" exist.   If no terms with a constant RHS
+** exist, try to return a term that does not use WO_EQUIV.
+*/
+SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
+  WhereClause *pWC,     /* The WHERE clause to be searched */
+  int iCur,             /* Cursor number of LHS */
+  int iColumn,          /* Column number of LHS */
+  Bitmask notReady,     /* RHS must not overlap with this mask */
+  u32 op,               /* Mask of WO_xx values describing operator */
+  Index *pIdx           /* Must be compatible with this index, if not NULL */
+){
+  WhereTerm *pResult = 0;
+  WhereTerm *p;
+  WhereScan scan;
+
+  p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
+  op &= WO_EQ|WO_IS;
+  while( p ){
+    if( (p->prereqRight & notReady)==0 ){
+      if( p->prereqRight==0 && (p->eOperator&op)!=0 ){
+        testcase( p->eOperator & WO_IS );
+        return p;
+      }
+      if( pResult==0 ) pResult = p;
+    }
+    p = whereScanNext(&scan);
+  }
+  return pResult;
+}
+
+/*
+** This function searches pList for an entry that matches the iCol-th column
+** of index pIdx.
+**
+** If such an expression is found, its index in pList->a[] is returned. If
+** no expression is found, -1 is returned.
+*/
+static int findIndexCol(
+  Parse *pParse,                  /* Parse context */
+  ExprList *pList,                /* Expression list to search */
+  int iBase,                      /* Cursor for table associated with pIdx */
+  Index *pIdx,                    /* Index to match column of */
+  int iCol                        /* Column of index to match */
+){
+  int i;
+  const char *zColl = pIdx->azColl[iCol];
+
+  for(i=0; i<pList->nExpr; i++){
+    Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
+    if( p->op==TK_COLUMN
+     && p->iColumn==pIdx->aiColumn[iCol]
+     && p->iTable==iBase
+    ){
+      CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
+      if( pColl && 0==sqlite3StrICmp(pColl->zName, zColl) ){
+        return i;
+      }
+    }
+  }
+
+  return -1;
+}
+
+/*
+** Return TRUE if the iCol-th column of index pIdx is NOT NULL
+*/
+static int indexColumnNotNull(Index *pIdx, int iCol){
+  int j;
+  assert( pIdx!=0 );
+  assert( iCol>=0 && iCol<pIdx->nColumn );
+  j = pIdx->aiColumn[iCol];
+  if( j>=0 ){
+    return pIdx->pTable->aCol[j].notNull;
+  }else if( j==(-1) ){
+    return 1;
+  }else{
+    assert( j==(-2) );
+    return 0;  /* Assume an indexed expression can always yield a NULL */
+
+  }
+}
+
+/*
+** Return true if the DISTINCT expression-list passed as the third argument
+** is redundant.
+**
+** A DISTINCT list is redundant if any subset of the columns in the
+** DISTINCT list are collectively unique and individually non-null.
+*/
+static int isDistinctRedundant(
+  Parse *pParse,            /* Parsing context */
+  SrcList *pTabList,        /* The FROM clause */
+  WhereClause *pWC,         /* The WHERE clause */
+  ExprList *pDistinct       /* The result set that needs to be DISTINCT */
+){
+  Table *pTab;
+  Index *pIdx;
+  int i;                          
+  int iBase;
+
+  /* If there is more than one table or sub-select in the FROM clause of
+  ** this query, then it will not be possible to show that the DISTINCT 
+  ** clause is redundant. */
+  if( pTabList->nSrc!=1 ) return 0;
+  iBase = pTabList->a[0].iCursor;
+  pTab = pTabList->a[0].pTab;
+
+  /* If any of the expressions is an IPK column on table iBase, then return 
+  ** true. Note: The (p->iTable==iBase) part of this test may be false if the
+  ** current SELECT is a correlated sub-query.
+  */
+  for(i=0; i<pDistinct->nExpr; i++){
+    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
+    if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
+  }
+
+  /* Loop through all indices on the table, checking each to see if it makes
+  ** the DISTINCT qualifier redundant. It does so if:
+  **
+  **   1. The index is itself UNIQUE, and
+  **
+  **   2. All of the columns in the index are either part of the pDistinct
+  **      list, or else the WHERE clause contains a term of the form "col=X",
+  **      where X is a constant value. The collation sequences of the
+  **      comparison and select-list expressions must match those of the index.
+  **
+  **   3. All of those index columns for which the WHERE clause does not
+  **      contain a "col=X" term are subject to a NOT NULL constraint.
+  */
+  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+    if( !IsUniqueIndex(pIdx) ) continue;
+    for(i=0; i<pIdx->nKeyCol; i++){
+      if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){
+        if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;
+        if( indexColumnNotNull(pIdx, i)==0 ) break;
+      }
+    }
+    if( i==pIdx->nKeyCol ){
+      /* This index implies that the DISTINCT qualifier is redundant. */
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+
+/*
+** Estimate the logarithm of the input value to base 2.
+*/
+static LogEst estLog(LogEst N){
+  return N<=10 ? 0 : sqlite3LogEst(N) - 33;
+}
+
+/*
+** Convert OP_Column opcodes to OP_Copy in previously generated code.
+**
+** This routine runs over generated VDBE code and translates OP_Column
+** opcodes into OP_Copy when the table is being accessed via co-routine 
+** instead of via table lookup.
+**
+** If the bIncrRowid parameter is 0, then any OP_Rowid instructions on
+** cursor iTabCur are transformed into OP_Null. Or, if bIncrRowid is non-zero,
+** then each OP_Rowid is transformed into an instruction to increment the
+** value stored in its output register.
+*/
+static void translateColumnToCopy(
+  Vdbe *v,            /* The VDBE containing code to translate */
+  int iStart,         /* Translate from this opcode to the end */
+  int iTabCur,        /* OP_Column/OP_Rowid references to this table */
+  int iRegister,      /* The first column is in this register */
+  int bIncrRowid      /* If non-zero, transform OP_rowid to OP_AddImm(1) */
+){
+  VdbeOp *pOp = sqlite3VdbeGetOp(v, iStart);
+  int iEnd = sqlite3VdbeCurrentAddr(v);
+  for(; iStart<iEnd; iStart++, pOp++){
+    if( pOp->p1!=iTabCur ) continue;
+    if( pOp->opcode==OP_Column ){
+      pOp->opcode = OP_Copy;
+      pOp->p1 = pOp->p2 + iRegister;
+      pOp->p2 = pOp->p3;
+      pOp->p3 = 0;
+    }else if( pOp->opcode==OP_Rowid ){
+      if( bIncrRowid ){
+        /* Increment the value stored in the P2 operand of the OP_Rowid. */
+        pOp->opcode = OP_AddImm;
+        pOp->p1 = pOp->p2;
+        pOp->p2 = 1;
+      }else{
+        pOp->opcode = OP_Null;
+        pOp->p1 = 0;
+        pOp->p3 = 0;
+      }
+    }
+  }
+}
+
+/*
+** Two routines for printing the content of an sqlite3_index_info
+** structure.  Used for testing and debugging only.  If neither
+** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
+** are no-ops.
+*/
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
+static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; i<p->nConstraint; i++){
+    sqlite3DebugPrintf("  constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
+       i,
+       p->aConstraint[i].iColumn,
+       p->aConstraint[i].iTermOffset,
+       p->aConstraint[i].op,
+       p->aConstraint[i].usable);
+  }
+  for(i=0; i<p->nOrderBy; i++){
+    sqlite3DebugPrintf("  orderby[%d]: col=%d desc=%d\n",
+       i,
+       p->aOrderBy[i].iColumn,
+       p->aOrderBy[i].desc);
+  }
+}
+static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
+  int i;
+  if( !sqlite3WhereTrace ) return;
+  for(i=0; i<p->nConstraint; i++){
+    sqlite3DebugPrintf("  usage[%d]: argvIdx=%d omit=%d\n",
+       i,
+       p->aConstraintUsage[i].argvIndex,
+       p->aConstraintUsage[i].omit);
+  }
+  sqlite3DebugPrintf("  idxNum=%d\n", p->idxNum);
+  sqlite3DebugPrintf("  idxStr=%s\n", p->idxStr);
+  sqlite3DebugPrintf("  orderByConsumed=%d\n", p->orderByConsumed);
+  sqlite3DebugPrintf("  estimatedCost=%g\n", p->estimatedCost);
+  sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);
+}
+#else
+#define TRACE_IDX_INPUTS(A)
+#define TRACE_IDX_OUTPUTS(A)
+#endif
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+/*
+** Return TRUE if the WHERE clause term pTerm is of a form where it
+** could be used with an index to access pSrc, assuming an appropriate
+** index existed.
+*/
+static int termCanDriveIndex(
+  WhereTerm *pTerm,              /* WHERE clause term to check */
+  struct SrcList_item *pSrc,     /* Table we are trying to access */
+  Bitmask notReady               /* Tables in outer loops of the join */
+){
+  char aff;
+  if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
+  if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;
+  if( (pTerm->prereqRight & notReady)!=0 ) return 0;
+  if( pTerm->u.leftColumn<0 ) return 0;
+  aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
+  if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
+  testcase( pTerm->pExpr->op==TK_IS );
+  return 1;
+}
+#endif
+
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+/*
+** Generate code to construct the Index object for an automatic index
+** and to set up the WhereLevel object pLevel so that the code generator
+** makes use of the automatic index.
+*/
+static void constructAutomaticIndex(
+  Parse *pParse,              /* The parsing context */
+  WhereClause *pWC,           /* The WHERE clause */
+  struct SrcList_item *pSrc,  /* The FROM clause term to get the next index */
+  Bitmask notReady,           /* Mask of cursors that are not available */
+  WhereLevel *pLevel          /* Write new index here */
+){
+  int nKeyCol;                /* Number of columns in the constructed index */
+  WhereTerm *pTerm;           /* A single term of the WHERE clause */
+  WhereTerm *pWCEnd;          /* End of pWC->a[] */
+  Index *pIdx;                /* Object describing the transient index */
+  Vdbe *v;                    /* Prepared statement under construction */
+  int addrInit;               /* Address of the initialization bypass jump */
+  Table *pTable;              /* The table being indexed */
+  int addrTop;                /* Top of the index fill loop */
+  int regRecord;              /* Register holding an index record */
+  int n;                      /* Column counter */
+  int i;                      /* Loop counter */
+  int mxBitCol;               /* Maximum column in pSrc->colUsed */
+  CollSeq *pColl;             /* Collating sequence to on a column */
+  WhereLoop *pLoop;           /* The Loop object */
+  char *zNotUsed;             /* Extra space on the end of pIdx */
+  Bitmask idxCols;            /* Bitmap of columns used for indexing */
+  Bitmask extraCols;          /* Bitmap of additional columns */
+  u8 sentWarning = 0;         /* True if a warnning has been issued */
+  Expr *pPartial = 0;         /* Partial Index Expression */
+  int iContinue = 0;          /* Jump here to skip excluded rows */
+  struct SrcList_item *pTabItem;  /* FROM clause term being indexed */
+  int addrCounter = 0;        /* Address where integer counter is initialized */
+  int regBase;                /* Array of registers where record is assembled */
+
+  /* Generate code to skip over the creation and initialization of the
+  ** transient index on 2nd and subsequent iterations of the loop. */
+  v = pParse->pVdbe;
+  assert( v!=0 );
+  addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v);
+
+  /* Count the number of columns that will be added to the index
+  ** and used to match WHERE clause constraints */
+  nKeyCol = 0;
+  pTable = pSrc->pTab;
+  pWCEnd = &pWC->a[pWC->nTerm];
+  pLoop = pLevel->pWLoop;
+  idxCols = 0;
+  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
+    Expr *pExpr = pTerm->pExpr;
+    assert( !ExprHasProperty(pExpr, EP_FromJoin)    /* prereq always non-zero */
+         || pExpr->iRightJoinTable!=pSrc->iCursor   /*   for the right-hand   */
+         || pLoop->prereq!=0 );                     /*   table of a LEFT JOIN */
+    if( pLoop->prereq==0
+     && (pTerm->wtFlags & TERM_VIRTUAL)==0
+     && !ExprHasProperty(pExpr, EP_FromJoin)
+     && sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){
+      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
+                                sqlite3ExprDup(pParse->db, pExpr, 0));
+    }
+    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
+      int iCol = pTerm->u.leftColumn;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS );
+      testcase( iCol==BMS-1 );
+      if( !sentWarning ){
+        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
+            "automatic index on %s(%s)", pTable->zName,
+            pTable->aCol[iCol].zName);
+        sentWarning = 1;
+      }
+      if( (idxCols & cMask)==0 ){
+        if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
+          goto end_auto_index_create;
+        }
+        pLoop->aLTerm[nKeyCol++] = pTerm;
+        idxCols |= cMask;
+      }
+    }
+  }
+  assert( nKeyCol>0 );
+  pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
+  pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
+                     | WHERE_AUTO_INDEX;
+
+  /* Count the number of additional columns needed to create a
+  ** covering index.  A "covering index" is an index that contains all
+  ** columns that are needed by the query.  With a covering index, the
+  ** original table never needs to be accessed.  Automatic indices must
+  ** be a covering index because the index will not be updated if the
+  ** original table changes and the index and table cannot both be used
+  ** if they go out of sync.
+  */
+  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
+  mxBitCol = MIN(BMS-1,pTable->nCol);
+  testcase( pTable->nCol==BMS-1 );
+  testcase( pTable->nCol==BMS-2 );
+  for(i=0; i<mxBitCol; i++){
+    if( extraCols & MASKBIT(i) ) nKeyCol++;
+  }
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
+    nKeyCol += pTable->nCol - BMS + 1;
+  }
+
+  /* Construct the Index object to describe this index */
+  pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
+  if( pIdx==0 ) goto end_auto_index_create;
+  pLoop->u.btree.pIndex = pIdx;
+  pIdx->zName = "auto-index";
+  pIdx->pTable = pTable;
+  n = 0;
+  idxCols = 0;
+  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
+    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
+      int iCol = pTerm->u.leftColumn;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS-1 );
+      testcase( iCol==BMS );
+      if( (idxCols & cMask)==0 ){
+        Expr *pX = pTerm->pExpr;
+        idxCols |= cMask;
+        pIdx->aiColumn[n] = pTerm->u.leftColumn;
+        pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
+        pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
+        n++;
+      }
+    }
+  }
+  assert( (u32)n==pLoop->u.btree.nEq );
+
+  /* Add additional columns needed to make the automatic index into
+  ** a covering index */
+  for(i=0; i<mxBitCol; i++){
+    if( extraCols & MASKBIT(i) ){
+      pIdx->aiColumn[n] = i;
+      pIdx->azColl[n] = sqlite3StrBINARY;
+      n++;
+    }
+  }
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
+    for(i=BMS-1; i<pTable->nCol; i++){
+      pIdx->aiColumn[n] = i;
+      pIdx->azColl[n] = sqlite3StrBINARY;
+      n++;
+    }
+  }
+  assert( n==nKeyCol );
+  pIdx->aiColumn[n] = XN_ROWID;
+  pIdx->azColl[n] = sqlite3StrBINARY;
+
+  /* Create the automatic index */
+  assert( pLevel->iIdxCur>=0 );
+  pLevel->iIdxCur = pParse->nTab++;
+  sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
+  sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+  VdbeComment((v, "for %s", pTable->zName));
+
+  /* Fill the automatic index with content */
+  sqlite3ExprCachePush(pParse);
+  pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
+  if( pTabItem->fg.viaCoroutine ){
+    int regYield = pTabItem->regReturn;
+    addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
+    sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
+    addrTop =  sqlite3VdbeAddOp1(v, OP_Yield, regYield);
+    VdbeCoverage(v);
+    VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName));
+  }else{
+    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
+  }
+  if( pPartial ){
+    iContinue = sqlite3VdbeMakeLabel(v);
+    sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
+    pLoop->wsFlags |= WHERE_PARTIALIDX;
+  }
+  regRecord = sqlite3GetTempReg(pParse);
+  regBase = sqlite3GenerateIndexKey(
+      pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
+  );
+  sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
+  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
+  if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
+  if( pTabItem->fg.viaCoroutine ){
+    sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
+    translateColumnToCopy(v, addrTop, pLevel->iTabCur, pTabItem->regResult, 1);
+    sqlite3VdbeGoto(v, addrTop);
+    pTabItem->fg.viaCoroutine = 0;
+  }else{
+    sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
+  }
+  sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
+  sqlite3VdbeJumpHere(v, addrTop);
+  sqlite3ReleaseTempReg(pParse, regRecord);
+  sqlite3ExprCachePop(pParse);
+  
+  /* Jump here when skipping the initialization */
+  sqlite3VdbeJumpHere(v, addrInit);
+
+end_auto_index_create:
+  sqlite3ExprDelete(pParse->db, pPartial);
+}
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Allocate and populate an sqlite3_index_info structure. It is the 
+** responsibility of the caller to eventually release the structure
+** by passing the pointer returned by this function to sqlite3_free().
+*/
+static sqlite3_index_info *allocateIndexInfo(
+  Parse *pParse,
+  WhereClause *pWC,
+  Bitmask mUnusable,              /* Ignore terms with these prereqs */
+  struct SrcList_item *pSrc,
+  ExprList *pOrderBy
+){
+  int i, j;
+  int nTerm;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_orderby *pIdxOrderBy;
+  struct sqlite3_index_constraint_usage *pUsage;
+  WhereTerm *pTerm;
+  int nOrderBy;
+  sqlite3_index_info *pIdxInfo;
+
+  /* Count the number of possible WHERE clause constraints referring
+  ** to this virtual table */
+  for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    if( pTerm->leftCursor != pSrc->iCursor ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
+    if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
+    nTerm++;
+  }
+
+  /* If the ORDER BY clause contains only columns in the current 
+  ** virtual table then allocate space for the aOrderBy part of
+  ** the sqlite3_index_info structure.
+  */
+  nOrderBy = 0;
+  if( pOrderBy ){
+    int n = pOrderBy->nExpr;
+    for(i=0; i<n; i++){
+      Expr *pExpr = pOrderBy->a[i].pExpr;
+      if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
+    }
+    if( i==n){
+      nOrderBy = n;
+    }
+  }
+
+  /* Allocate the sqlite3_index_info structure
+  */
+  pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)
+                           + (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm
+                           + sizeof(*pIdxOrderBy)*nOrderBy );
+  if( pIdxInfo==0 ){
+    sqlite3ErrorMsg(pParse, "out of memory");
+    return 0;
+  }
+
+  /* Initialize the structure.  The sqlite3_index_info structure contains
+  ** many fields that are declared "const" to prevent xBestIndex from
+  ** changing them.  We have to do some funky casting in order to
+  ** initialize those fields.
+  */
+  pIdxCons = (struct sqlite3_index_constraint*)&pIdxInfo[1];
+  pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
+  pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
+  *(int*)&pIdxInfo->nConstraint = nTerm;
+  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
+  *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;
+  *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;
+  *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =
+                                                                   pUsage;
+
+  for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    u8 op;
+    if( pTerm->leftCursor != pSrc->iCursor ) continue;
+    if( pTerm->prereqRight & mUnusable ) continue;
+    assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
+    testcase( pTerm->eOperator & WO_IN );
+    testcase( pTerm->eOperator & WO_IS );
+    testcase( pTerm->eOperator & WO_ISNULL );
+    testcase( pTerm->eOperator & WO_ALL );
+    if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
+    if( pTerm->wtFlags & TERM_VNULL ) continue;
+    assert( pTerm->u.leftColumn>=(-1) );
+    pIdxCons[j].iColumn = pTerm->u.leftColumn;
+    pIdxCons[j].iTermOffset = i;
+    op = (u8)pTerm->eOperator & WO_ALL;
+    if( op==WO_IN ) op = WO_EQ;
+    if( op==WO_MATCH ){
+      op = pTerm->eMatchOp;
+    }
+    pIdxCons[j].op = op;
+    /* The direct assignment in the previous line is possible only because
+    ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical.  The
+    ** following asserts verify this fact. */
+    assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
+    assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
+    assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
+    assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
+    assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
+    assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH );
+    assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) );
+    j++;
+  }
+  for(i=0; i<nOrderBy; i++){
+    Expr *pExpr = pOrderBy->a[i].pExpr;
+    pIdxOrderBy[i].iColumn = pExpr->iColumn;
+    pIdxOrderBy[i].desc = pOrderBy->a[i].sortOrder;
+  }
+
+  return pIdxInfo;
+}
+
+/*
+** The table object reference passed as the second argument to this function
+** must represent a virtual table. This function invokes the xBestIndex()
+** method of the virtual table with the sqlite3_index_info object that
+** comes in as the 3rd argument to this function.
+**
+** If an error occurs, pParse is populated with an error message and a
+** non-zero value is returned. Otherwise, 0 is returned and the output
+** part of the sqlite3_index_info structure is left populated.
+**
+** Whether or not an error is returned, it is the responsibility of the
+** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates
+** that this is required.
+*/
+static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
+  sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
+  int i;
+  int rc;
+
+  TRACE_IDX_INPUTS(p);
+  rc = pVtab->pModule->xBestIndex(pVtab, p);
+  TRACE_IDX_OUTPUTS(p);
+
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_NOMEM ){
+      pParse->db->mallocFailed = 1;
+    }else if( !pVtab->zErrMsg ){
+      sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
+    }else{
+      sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
+    }
+  }
+  sqlite3_free(pVtab->zErrMsg);
+  pVtab->zErrMsg = 0;
+
+  for(i=0; i<p->nConstraint; i++){
+    if( !p->aConstraint[i].usable && p->aConstraintUsage[i].argvIndex>0 ){
+      sqlite3ErrorMsg(pParse, 
+          "table %s: xBestIndex returned an invalid plan", pTab->zName);
+    }
+  }
+
+  return pParse->nErr;
+}
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the location of a particular key among all keys in an
+** index.  Store the results in aStat as follows:
+**
+**    aStat[0]      Est. number of rows less than pRec
+**    aStat[1]      Est. number of rows equal to pRec
+**
+** Return the index of the sample that is the smallest sample that
+** is greater than or equal to pRec. Note that this index is not an index
+** into the aSample[] array - it is an index into a virtual set of samples
+** based on the contents of aSample[] and the number of fields in record 
+** pRec. 
+*/
+static int whereKeyStats(
+  Parse *pParse,              /* Database connection */
+  Index *pIdx,                /* Index to consider domain of */
+  UnpackedRecord *pRec,       /* Vector of values to consider */
+  int roundUp,                /* Round up if true.  Round down if false */
+  tRowcnt *aStat              /* OUT: stats written here */
+){
+  IndexSample *aSample = pIdx->aSample;
+  int iCol;                   /* Index of required stats in anEq[] etc. */
+  int i;                      /* Index of first sample >= pRec */
+  int iSample;                /* Smallest sample larger than or equal to pRec */
+  int iMin = 0;               /* Smallest sample not yet tested */
+  int iTest;                  /* Next sample to test */
+  int res;                    /* Result of comparison operation */
+  int nField;                 /* Number of fields in pRec */
+  tRowcnt iLower = 0;         /* anLt[] + anEq[] of largest sample pRec is > */
+
+#ifndef SQLITE_DEBUG
+  UNUSED_PARAMETER( pParse );
+#endif
+  assert( pRec!=0 );
+  assert( pIdx->nSample>0 );
+  assert( pRec->nField>0 && pRec->nField<=pIdx->nSampleCol );
+
+  /* Do a binary search to find the first sample greater than or equal
+  ** to pRec. If pRec contains a single field, the set of samples to search
+  ** is simply the aSample[] array. If the samples in aSample[] contain more
+  ** than one fields, all fields following the first are ignored.
+  **
+  ** If pRec contains N fields, where N is more than one, then as well as the
+  ** samples in aSample[] (truncated to N fields), the search also has to
+  ** consider prefixes of those samples. For example, if the set of samples
+  ** in aSample is:
+  **
+  **     aSample[0] = (a, 5) 
+  **     aSample[1] = (a, 10) 
+  **     aSample[2] = (b, 5) 
+  **     aSample[3] = (c, 100) 
+  **     aSample[4] = (c, 105)
+  **
+  ** Then the search space should ideally be the samples above and the 
+  ** unique prefixes [a], [b] and [c]. But since that is hard to organize, 
+  ** the code actually searches this set:
+  **
+  **     0: (a) 
+  **     1: (a, 5) 
+  **     2: (a, 10) 
+  **     3: (a, 10) 
+  **     4: (b) 
+  **     5: (b, 5) 
+  **     6: (c) 
+  **     7: (c, 100) 
+  **     8: (c, 105)
+  **     9: (c, 105)
+  **
+  ** For each sample in the aSample[] array, N samples are present in the
+  ** effective sample array. In the above, samples 0 and 1 are based on 
+  ** sample aSample[0]. Samples 2 and 3 on aSample[1] etc.
+  **
+  ** Often, sample i of each block of N effective samples has (i+1) fields.
+  ** Except, each sample may be extended to ensure that it is greater than or
+  ** equal to the previous sample in the array. For example, in the above, 
+  ** sample 2 is the first sample of a block of N samples, so at first it 
+  ** appears that it should be 1 field in size. However, that would make it 
+  ** smaller than sample 1, so the binary search would not work. As a result, 
+  ** it is extended to two fields. The duplicates that this creates do not 
+  ** cause any problems.
+  */
+  nField = pRec->nField;
+  iCol = 0;
+  iSample = pIdx->nSample * nField;
+  do{
+    int iSamp;                    /* Index in aSample[] of test sample */
+    int n;                        /* Number of fields in test sample */
+
+    iTest = (iMin+iSample)/2;
+    iSamp = iTest / nField;
+    if( iSamp>0 ){
+      /* The proposed effective sample is a prefix of sample aSample[iSamp].
+      ** Specifically, the shortest prefix of at least (1 + iTest%nField) 
+      ** fields that is greater than the previous effective sample.  */
+      for(n=(iTest % nField) + 1; n<nField; n++){
+        if( aSample[iSamp-1].anLt[n-1]!=aSample[iSamp].anLt[n-1] ) break;
+      }
+    }else{
+      n = iTest + 1;
+    }
+
+    pRec->nField = n;
+    res = sqlite3VdbeRecordCompare(aSample[iSamp].n, aSample[iSamp].p, pRec);
+    if( res<0 ){
+      iLower = aSample[iSamp].anLt[n-1] + aSample[iSamp].anEq[n-1];
+      iMin = iTest+1;
+    }else if( res==0 && n<nField ){
+      iLower = aSample[iSamp].anLt[n-1];
+      iMin = iTest+1;
+      res = -1;
+    }else{
+      iSample = iTest;
+      iCol = n-1;
+    }
+  }while( res && iMin<iSample );
+  i = iSample / nField;
+
+#ifdef SQLITE_DEBUG
+  /* The following assert statements check that the binary search code
+  ** above found the right answer. This block serves no purpose other
+  ** than to invoke the asserts.  */
+  if( pParse->db->mallocFailed==0 ){
+    if( res==0 ){
+      /* If (res==0) is true, then pRec must be equal to sample i. */
+      assert( i<pIdx->nSample );
+      assert( iCol==nField-1 );
+      pRec->nField = nField;
+      assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec) 
+           || pParse->db->mallocFailed 
+      );
+    }else{
+      /* Unless i==pIdx->nSample, indicating that pRec is larger than
+      ** all samples in the aSample[] array, pRec must be smaller than the
+      ** (iCol+1) field prefix of sample i.  */
+      assert( i<=pIdx->nSample && i>=0 );
+      pRec->nField = iCol+1;
+      assert( i==pIdx->nSample 
+           || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
+           || pParse->db->mallocFailed );
+
+      /* if i==0 and iCol==0, then record pRec is smaller than all samples
+      ** in the aSample[] array. Otherwise, if (iCol>0) then pRec must
+      ** be greater than or equal to the (iCol) field prefix of sample i.
+      ** If (i>0), then pRec must also be greater than sample (i-1).  */
+      if( iCol>0 ){
+        pRec->nField = iCol;
+        assert( sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)<=0
+             || pParse->db->mallocFailed );
+      }
+      if( i>0 ){
+        pRec->nField = nField;
+        assert( sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
+             || pParse->db->mallocFailed );
+      }
+    }
+  }
+#endif /* ifdef SQLITE_DEBUG */
+
+  if( res==0 ){
+    /* Record pRec is equal to sample i */
+    assert( iCol==nField-1 );
+    aStat[0] = aSample[i].anLt[iCol];
+    aStat[1] = aSample[i].anEq[iCol];
+  }else{
+    /* At this point, the (iCol+1) field prefix of aSample[i] is the first 
+    ** sample that is greater than pRec. Or, if i==pIdx->nSample then pRec
+    ** is larger than all samples in the array. */
+    tRowcnt iUpper, iGap;
+    if( i>=pIdx->nSample ){
+      iUpper = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
+    }else{
+      iUpper = aSample[i].anLt[iCol];
+    }
+
+    if( iLower>=iUpper ){
+      iGap = 0;
+    }else{
+      iGap = iUpper - iLower;
+    }
+    if( roundUp ){
+      iGap = (iGap*2)/3;
+    }else{
+      iGap = iGap/3;
+    }
+    aStat[0] = iLower + iGap;
+    aStat[1] = pIdx->aAvgEq[iCol];
+  }
+
+  /* Restore the pRec->nField value before returning.  */
+  pRec->nField = nField;
+  return i;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** If it is not NULL, pTerm is a term that provides an upper or lower
+** bound on a range scan. Without considering pTerm, it is estimated 
+** that the scan will visit nNew rows. This function returns the number
+** estimated to be visited after taking pTerm into account.
+**
+** If the user explicitly specified a likelihood() value for this term,
+** then the return value is the likelihood multiplied by the number of
+** input rows. Otherwise, this function assumes that an "IS NOT NULL" term
+** has a likelihood of 0.50, and any other term a likelihood of 0.25.
+*/
+static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
+  LogEst nRet = nNew;
+  if( pTerm ){
+    if( pTerm->truthProb<=0 ){
+      nRet += pTerm->truthProb;
+    }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){
+      nRet -= 20;        assert( 20==sqlite3LogEst(4) );
+    }
+  }
+  return nRet;
+}
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Return the affinity for a single column of an index.
+*/
+static char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){
+  assert( iCol>=0 && iCol<pIdx->nColumn );
+  if( !pIdx->zColAff ){
+    if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;
+  }
+  return pIdx->zColAff[iCol];
+}
+#endif
+
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/* 
+** This function is called to estimate the number of rows visited by a
+** range-scan on a skip-scan index. For example:
+**
+**   CREATE INDEX i1 ON t1(a, b, c);
+**   SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;
+**
+** Value pLoop->nOut is currently set to the estimated number of rows 
+** visited for scanning (a=? AND b=?). This function reduces that estimate 
+** by some factor to account for the (c BETWEEN ? AND ?) expression based
+** on the stat4 data for the index. this scan will be peformed multiple 
+** times (once for each (a,b) combination that matches a=?) is dealt with 
+** by the caller.
+**
+** It does this by scanning through all stat4 samples, comparing values
+** extracted from pLower and pUpper with the corresponding column in each
+** sample. If L and U are the number of samples found to be less than or
+** equal to the values extracted from pLower and pUpper respectively, and
+** N is the total number of samples, the pLoop->nOut value is adjusted
+** as follows:
+**
+**   nOut = nOut * ( min(U - L, 1) / N )
+**
+** If pLower is NULL, or a value cannot be extracted from the term, L is
+** set to zero. If pUpper is NULL, or a value cannot be extracted from it,
+** U is set to N.
+**
+** Normally, this function sets *pbDone to 1 before returning. However,
+** if no value can be extracted from either pLower or pUpper (and so the
+** estimate of the number of rows delivered remains unchanged), *pbDone
+** is left as is.
+**
+** If an error occurs, an SQLite error code is returned. Otherwise, 
+** SQLITE_OK.
+*/
+static int whereRangeSkipScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
+  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
+  WhereLoop *pLoop,    /* Update the .nOut value of this loop */
+  int *pbDone          /* Set to true if at least one expr. value extracted */
+){
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+  sqlite3 *db = pParse->db;
+  int nLower = -1;
+  int nUpper = p->nSample+1;
+  int rc = SQLITE_OK;
+  u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);
+  CollSeq *pColl;
+  
+  sqlite3_value *p1 = 0;          /* Value extracted from pLower */
+  sqlite3_value *p2 = 0;          /* Value extracted from pUpper */
+  sqlite3_value *pVal = 0;        /* Value extracted from record */
+
+  pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);
+  if( pLower ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);
+    nLower = 0;
+  }
+  if( pUpper && rc==SQLITE_OK ){
+    rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);
+    nUpper = p2 ? 0 : p->nSample;
+  }
+
+  if( p1 || p2 ){
+    int i;
+    int nDiff;
+    for(i=0; rc==SQLITE_OK && i<p->nSample; i++){
+      rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);
+      if( rc==SQLITE_OK && p1 ){
+        int res = sqlite3MemCompare(p1, pVal, pColl);
+        if( res>=0 ) nLower++;
+      }
+      if( rc==SQLITE_OK && p2 ){
+        int res = sqlite3MemCompare(p2, pVal, pColl);
+        if( res>=0 ) nUpper++;
+      }
+    }
+    nDiff = (nUpper - nLower);
+    if( nDiff<=0 ) nDiff = 1;
+
+    /* If there is both an upper and lower bound specified, and the 
+    ** comparisons indicate that they are close together, use the fallback
+    ** method (assume that the scan visits 1/64 of the rows) for estimating
+    ** the number of rows visited. Otherwise, estimate the number of rows
+    ** using the method described in the header comment for this function. */
+    if( nDiff!=1 || pUpper==0 || pLower==0 ){
+      int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));
+      pLoop->nOut -= nAdjust;
+      *pbDone = 1;
+      WHERETRACE(0x10, ("range skip-scan regions: %u..%u  adjust=%d est=%d\n",
+                           nLower, nUpper, nAdjust*-1, pLoop->nOut));
+    }
+
+  }else{
+    assert( *pbDone==0 );
+  }
+
+  sqlite3ValueFree(p1);
+  sqlite3ValueFree(p2);
+  sqlite3ValueFree(pVal);
+
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+/*
+** This function is used to estimate the number of rows that will be visited
+** by scanning an index for a range of values. The range may have an upper
+** bound, a lower bound, or both. The WHERE clause terms that set the upper
+** and lower bounds are represented by pLower and pUpper respectively. For
+** example, assuming that index p is on t1(a):
+**
+**   ... FROM t1 WHERE a > ? AND a < ? ...
+**                    |_____|   |_____|
+**                       |         |
+**                     pLower    pUpper
+**
+** If either of the upper or lower bound is not present, then NULL is passed in
+** place of the corresponding WhereTerm.
+**
+** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
+** column subject to the range constraint. Or, equivalently, the number of
+** equality constraints optimized by the proposed index scan. For example,
+** assuming index p is on t1(a, b), and the SQL query is:
+**
+**   ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
+**
+** then nEq is set to 1 (as the range restricted column, b, is the second 
+** left-most column of the index). Or, if the query is:
+**
+**   ... FROM t1 WHERE a > ? AND a < ? ...
+**
+** then nEq is set to 0.
+**
+** When this function is called, *pnOut is set to the sqlite3LogEst() of the
+** number of rows that the index scan is expected to visit without 
+** considering the range constraints. If nEq is 0, then *pnOut is the number of 
+** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
+** to account for the range constraints pLower and pUpper.
+** 
+** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
+** used, a single range inequality reduces the search space by a factor of 4. 
+** and a pair of constraints (x>? AND x<?) reduces the expected number of
+** rows visited by a factor of 64.
+*/
+static int whereRangeScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereLoopBuilder *pBuilder,
+  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
+  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
+  WhereLoop *pLoop     /* Modify the .nOut and maybe .rRun fields */
+){
+  int rc = SQLITE_OK;
+  int nOut = pLoop->nOut;
+  LogEst nNew;
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+  Index *p = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
+
+  if( p->nSample>0 && nEq<p->nSampleCol ){
+    if( nEq==pBuilder->nRecValid ){
+      UnpackedRecord *pRec = pBuilder->pRec;
+      tRowcnt a[2];
+      u8 aff;
+
+      /* Variable iLower will be set to the estimate of the number of rows in 
+      ** the index that are less than the lower bound of the range query. The
+      ** lower bound being the concatenation of $P and $L, where $P is the
+      ** key-prefix formed by the nEq values matched against the nEq left-most
+      ** columns of the index, and $L is the value in pLower.
+      **
+      ** Or, if pLower is NULL or $L cannot be extracted from it (because it
+      ** is not a simple variable or literal value), the lower bound of the
+      ** range is $P. Due to a quirk in the way whereKeyStats() works, even
+      ** if $L is available, whereKeyStats() is called for both ($P) and 
+      ** ($P:$L) and the larger of the two returned values is used.
+      **
+      ** Similarly, iUpper is to be set to the estimate of the number of rows
+      ** less than the upper bound of the range query. Where the upper bound
+      ** is either ($P) or ($P:$U). Again, even if $U is available, both values
+      ** of iUpper are requested of whereKeyStats() and the smaller used.
+      **
+      ** The number of rows between the two bounds is then just iUpper-iLower.
+      */
+      tRowcnt iLower;     /* Rows less than the lower bound */
+      tRowcnt iUpper;     /* Rows less than the upper bound */
+      int iLwrIdx = -2;   /* aSample[] for the lower bound */
+      int iUprIdx = -1;   /* aSample[] for the upper bound */
+
+      if( pRec ){
+        testcase( pRec->nField!=pBuilder->nRecValid );
+        pRec->nField = pBuilder->nRecValid;
+      }
+      aff = sqlite3IndexColumnAffinity(pParse->db, p, nEq);
+      assert( nEq!=p->nKeyCol || aff==SQLITE_AFF_INTEGER );
+      /* Determine iLower and iUpper using ($P) only. */
+      if( nEq==0 ){
+        iLower = 0;
+        iUpper = p->nRowEst0;
+      }else{
+        /* Note: this call could be optimized away - since the same values must 
+        ** have been requested when testing key $P in whereEqualScanEst().  */
+        whereKeyStats(pParse, p, pRec, 0, a);
+        iLower = a[0];
+        iUpper = a[0] + a[1];
+      }
+
+      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
+      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
+      assert( p->aSortOrder!=0 );
+      if( p->aSortOrder[nEq] ){
+        /* The roles of pLower and pUpper are swapped for a DESC index */
+        SWAP(WhereTerm*, pLower, pUpper);
+      }
+
+      /* If possible, improve on the iLower estimate using ($P:$L). */
+      if( pLower ){
+        int bOk;                    /* True if value is extracted from pExpr */
+        Expr *pExpr = pLower->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
+        if( rc==SQLITE_OK && bOk ){
+          tRowcnt iNew;
+          iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
+          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
+          if( iNew>iLower ) iLower = iNew;
+          nOut--;
+          pLower = 0;
+        }
+      }
+
+      /* If possible, improve on the iUpper estimate using ($P:$U). */
+      if( pUpper ){
+        int bOk;                    /* True if value is extracted from pExpr */
+        Expr *pExpr = pUpper->pExpr->pRight;
+        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
+        if( rc==SQLITE_OK && bOk ){
+          tRowcnt iNew;
+          iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
+          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
+          if( iNew<iUpper ) iUpper = iNew;
+          nOut--;
+          pUpper = 0;
+        }
+      }
+
+      pBuilder->pRec = pRec;
+      if( rc==SQLITE_OK ){
+        if( iUpper>iLower ){
+          nNew = sqlite3LogEst(iUpper - iLower);
+          /* TUNING:  If both iUpper and iLower are derived from the same
+          ** sample, then assume they are 4x more selective.  This brings
+          ** the estimated selectivity more in line with what it would be
+          ** if estimated without the use of STAT3/4 tables. */
+          if( iLwrIdx==iUprIdx ) nNew -= 20;  assert( 20==sqlite3LogEst(4) );
+        }else{
+          nNew = 10;        assert( 10==sqlite3LogEst(2) );
+        }
+        if( nNew<nOut ){
+          nOut = nNew;
+        }
+        WHERETRACE(0x10, ("STAT4 range scan: %u..%u  est=%d\n",
+                           (u32)iLower, (u32)iUpper, nOut));
+      }
+    }else{
+      int bDone = 0;
+      rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone);
+      if( bDone ) return rc;
+    }
+  }
+#else
+  UNUSED_PARAMETER(pParse);
+  UNUSED_PARAMETER(pBuilder);
+  assert( pLower || pUpper );
+#endif
+  assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
+  nNew = whereRangeAdjust(pLower, nOut);
+  nNew = whereRangeAdjust(pUpper, nNew);
+
+  /* TUNING: If there is both an upper and lower limit and neither limit
+  ** has an application-defined likelihood(), assume the range is
+  ** reduced by an additional 75%. This means that, by default, an open-ended
+  ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
+  ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
+  ** match 1/64 of the index. */ 
+  if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
+    nNew -= 20;
+  }
+
+  nOut -= (pLower!=0) + (pUpper!=0);
+  if( nNew<10 ) nNew = 10;
+  if( nNew<nOut ) nOut = nNew;
+#if defined(WHERETRACE_ENABLED)
+  if( pLoop->nOut>nOut ){
+    WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
+                    pLoop->nOut, nOut));
+  }
+#endif
+  pLoop->nOut = (LogEst)nOut;
+  return rc;
+}
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the number of rows that will be returned based on
+** an equality constraint x=VALUE and where that VALUE occurs in
+** the histogram data.  This only works when x is the left-most
+** column of an index and sqlite_stat3 histogram data is available
+** for that index.  When pExpr==NULL that means the constraint is
+** "x IS NULL" instead of "x=VALUE".
+**
+** Write the estimated row count into *pnRow and return SQLITE_OK. 
+** If unable to make an estimate, leave *pnRow unchanged and return
+** non-zero.
+**
+** This routine can fail if it is unable to load a collating sequence
+** required for string comparison, or if unable to allocate memory
+** for a UTF conversion required for comparison.  The error is stored
+** in the pParse structure.
+*/
+static int whereEqualScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereLoopBuilder *pBuilder,
+  Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
+){
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  int nEq = pBuilder->pNew->u.btree.nEq;
+  UnpackedRecord *pRec = pBuilder->pRec;
+  u8 aff;                   /* Column affinity */
+  int rc;                   /* Subfunction return code */
+  tRowcnt a[2];             /* Statistics */
+  int bOk;
+
+  assert( nEq>=1 );
+  assert( nEq<=p->nColumn );
+  assert( p->aSample!=0 );
+  assert( p->nSample>0 );
+  assert( pBuilder->nRecValid<nEq );
+
+  /* If values are not available for all fields of the index to the left
+  ** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */
+  if( pBuilder->nRecValid<(nEq-1) ){
+    return SQLITE_NOTFOUND;
+  }
+
+  /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
+  ** below would return the same value.  */
+  if( nEq>=p->nColumn ){
+    *pnRow = 1;
+    return SQLITE_OK;
+  }
+
+  aff = sqlite3IndexColumnAffinity(pParse->db, p, nEq-1);
+  rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq-1, &bOk);
+  pBuilder->pRec = pRec;
+  if( rc!=SQLITE_OK ) return rc;
+  if( bOk==0 ) return SQLITE_NOTFOUND;
+  pBuilder->nRecValid = nEq;
+
+  whereKeyStats(pParse, p, pRec, 0, a);
+  WHERETRACE(0x10,("equality scan regions: %d\n", (int)a[1]));
+  *pnRow = a[1];
+  
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+/*
+** Estimate the number of rows that will be returned based on
+** an IN constraint where the right-hand side of the IN operator
+** is a list of values.  Example:
+**
+**        WHERE x IN (1,2,3,4)
+**
+** Write the estimated row count into *pnRow and return SQLITE_OK. 
+** If unable to make an estimate, leave *pnRow unchanged and return
+** non-zero.
+**
+** This routine can fail if it is unable to load a collating sequence
+** required for string comparison, or if unable to allocate memory
+** for a UTF conversion required for comparison.  The error is stored
+** in the pParse structure.
+*/
+static int whereInScanEst(
+  Parse *pParse,       /* Parsing & code generating context */
+  WhereLoopBuilder *pBuilder,
+  ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
+){
+  Index *p = pBuilder->pNew->u.btree.pIndex;
+  i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);
+  int nRecValid = pBuilder->nRecValid;
+  int rc = SQLITE_OK;     /* Subfunction return code */
+  tRowcnt nEst;           /* Number of rows for a single term */
+  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
+  int i;                  /* Loop counter */
+
+  assert( p->aSample!=0 );
+  for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
+    nEst = nRow0;
+    rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
+    nRowEst += nEst;
+    pBuilder->nRecValid = nRecValid;
+  }
+
+  if( rc==SQLITE_OK ){
+    if( nRowEst > nRow0 ) nRowEst = nRow0;
+    *pnRow = nRowEst;
+    WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
+  }
+  assert( pBuilder->nRecValid==nRecValid );
+  return rc;
+}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
+
+#ifdef WHERETRACE_ENABLED
+/*
+** Print the content of a WhereTerm object
+*/
+static void whereTermPrint(WhereTerm *pTerm, int iTerm){
+  if( pTerm==0 ){
+    sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
+  }else{
+    char zType[4];
+    memcpy(zType, "...", 4);
+    if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
+    if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';
+    if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
+    sqlite3DebugPrintf(
+       "TERM-%-3d %p %s cursor=%-3d prob=%-3d op=0x%03x wtFlags=0x%04x\n",
+       iTerm, pTerm, zType, pTerm->leftCursor, pTerm->truthProb,
+       pTerm->eOperator, pTerm->wtFlags);
+    sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
+  }
+}
+#endif
+
+#ifdef WHERETRACE_ENABLED
+/*
+** Print a WhereLoop object for debugging purposes
+*/
+static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
+  WhereInfo *pWInfo = pWC->pWInfo;
+  int nb = 1+(pWInfo->pTabList->nSrc+7)/8;
+  struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
+  Table *pTab = pItem->pTab;
+  sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
+                     p->iTab, nb, p->maskSelf, nb, p->prereq);
+  sqlite3DebugPrintf(" %12s",
+                     pItem->zAlias ? pItem->zAlias : pTab->zName);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    const char *zName;
+    if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
+      if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
+        int i = sqlite3Strlen30(zName) - 1;
+        while( zName[i]!='_' ) i--;
+        zName += i;
+      }
+      sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
+    }else{
+      sqlite3DebugPrintf("%20s","");
+    }
+  }else{
+    char *z;
+    if( p->u.vtab.idxStr ){
+      z = sqlite3_mprintf("(%d,\"%s\",%x)",
+                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+    }else{
+      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
+    }
+    sqlite3DebugPrintf(" %-19s", z);
+    sqlite3_free(z);
+  }
+  if( p->wsFlags & WHERE_SKIPSCAN ){
+    sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
+  }else{
+    sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
+  }
+  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
+    int i;
+    for(i=0; i<p->nLTerm; i++){
+      whereTermPrint(p->aLTerm[i], i);
+    }
+  }
+}
+#endif
+
+/*
+** Convert bulk memory into a valid WhereLoop that can be passed
+** to whereLoopClear harmlessly.
+*/
+static void whereLoopInit(WhereLoop *p){
+  p->aLTerm = p->aLTermSpace;
+  p->nLTerm = 0;
+  p->nLSlot = ArraySize(p->aLTermSpace);
+  p->wsFlags = 0;
+}
+
+/*
+** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.
+*/
+static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
+  if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
+    if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
+      sqlite3_free(p->u.vtab.idxStr);
+      p->u.vtab.needFree = 0;
+      p->u.vtab.idxStr = 0;
+    }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
+      sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
+      sqlite3DbFree(db, p->u.btree.pIndex);
+      p->u.btree.pIndex = 0;
+    }
+  }
+}
+
+/*
+** Deallocate internal memory used by a WhereLoop object
+*/
+static void whereLoopClear(sqlite3 *db, WhereLoop *p){
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  whereLoopClearUnion(db, p);
+  whereLoopInit(p);
+}
+
+/*
+** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+*/
+static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
+  WhereTerm **paNew;
+  if( p->nLSlot>=n ) return SQLITE_OK;
+  n = (n+7)&~7;
+  paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n);
+  if( paNew==0 ) return SQLITE_NOMEM;
+  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  p->aLTerm = paNew;
+  p->nLSlot = n;
+  return SQLITE_OK;
+}
+
+/*
+** Transfer content from the second pLoop into the first.
+*/
+static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
+  whereLoopClearUnion(db, pTo);
+  if( whereLoopResize(db, pTo, pFrom->nLTerm) ){
+    memset(&pTo->u, 0, sizeof(pTo->u));
+    return SQLITE_NOMEM;
+  }
+  memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
+  memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
+  if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
+    pFrom->u.vtab.needFree = 0;
+  }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+    pFrom->u.btree.pIndex = 0;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Delete a WhereLoop object
+*/
+static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
+  whereLoopClear(db, p);
+  sqlite3DbFree(db, p);
+}
+
+/*
+** Free a WhereInfo structure
+*/
+static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
+  if( ALWAYS(pWInfo) ){
+    int i;
+    for(i=0; i<pWInfo->nLevel; i++){
+      WhereLevel *pLevel = &pWInfo->a[i];
+      if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
+        sqlite3DbFree(db, pLevel->u.in.aInLoop);
+      }
+    }
+    sqlite3WhereClauseClear(&pWInfo->sWC);
+    while( pWInfo->pLoops ){
+      WhereLoop *p = pWInfo->pLoops;
+      pWInfo->pLoops = p->pNextLoop;
+      whereLoopDelete(db, p);
+    }
+    sqlite3DbFree(db, pWInfo);
+  }
+}
+
+/*
+** Return TRUE if all of the following are true:
+**
+**   (1)  X has the same or lower cost that Y
+**   (2)  X is a proper subset of Y
+**   (3)  X skips at least as many columns as Y
+**
+** By "proper subset" we mean that X uses fewer WHERE clause terms
+** than Y and that every WHERE clause term used by X is also used
+** by Y.
+**
+** If X is a proper subset of Y then Y is a better choice and ought
+** to have a lower cost.  This routine returns TRUE when that cost 
+** relationship is inverted and needs to be adjusted.  The third rule
+** was added because if X uses skip-scan less than Y it still might
+** deserve a lower cost even if it is a proper subset of Y.
+*/
+static int whereLoopCheaperProperSubset(
+  const WhereLoop *pX,       /* First WhereLoop to compare */
+  const WhereLoop *pY        /* Compare against this WhereLoop */
+){
+  int i, j;
+  if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
+    return 0; /* X is not a subset of Y */
+  }
+  if( pY->nSkip > pX->nSkip ) return 0;
+  if( pX->rRun >= pY->rRun ){
+    if( pX->rRun > pY->rRun ) return 0;    /* X costs more than Y */
+    if( pX->nOut > pY->nOut ) return 0;    /* X costs more than Y */
+  }
+  for(i=pX->nLTerm-1; i>=0; i--){
+    if( pX->aLTerm[i]==0 ) continue;
+    for(j=pY->nLTerm-1; j>=0; j--){
+      if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
+    }
+    if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
+  }
+  return 1;  /* All conditions meet */
+}
+
+/*
+** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so
+** that:
+**
+**   (1) pTemplate costs less than any other WhereLoops that are a proper
+**       subset of pTemplate
+**
+**   (2) pTemplate costs more than any other WhereLoops for which pTemplate
+**       is a proper subset.
+**
+** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
+** WHERE clause terms than Y and that every WHERE clause term used by X is
+** also used by Y.
+*/
+static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
+  if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
+  for(; p; p=p->pNextLoop){
+    if( p->iTab!=pTemplate->iTab ) continue;
+    if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
+    if( whereLoopCheaperProperSubset(p, pTemplate) ){
+      /* Adjust pTemplate cost downward so that it is cheaper than its 
+      ** subset p. */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut - 1;
+    }else if( whereLoopCheaperProperSubset(pTemplate, p) ){
+      /* Adjust pTemplate cost upward so that it is costlier than p since
+      ** pTemplate is a proper subset of p */
+      WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
+                       pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
+      pTemplate->rRun = p->rRun;
+      pTemplate->nOut = p->nOut + 1;
+    }
+  }
+}
+
+/*
+** Search the list of WhereLoops in *ppPrev looking for one that can be
+** supplanted by pTemplate.
+**
+** Return NULL if the WhereLoop list contains an entry that can supplant
+** pTemplate, in other words if pTemplate does not belong on the list.
+**
+** If pX is a WhereLoop that pTemplate can supplant, then return the
+** link that points to pX.
+**
+** If pTemplate cannot supplant any existing element of the list but needs
+** to be added to the list, then return a pointer to the tail of the list.
+*/
+static WhereLoop **whereLoopFindLesser(
+  WhereLoop **ppPrev,
+  const WhereLoop *pTemplate
+){
+  WhereLoop *p;
+  for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
+    if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
+      /* If either the iTab or iSortIdx values for two WhereLoop are different
+      ** then those WhereLoops need to be considered separately.  Neither is
+      ** a candidate to replace the other. */
+      continue;
+    }
+    /* In the current implementation, the rSetup value is either zero
+    ** or the cost of building an automatic index (NlogN) and the NlogN
+    ** is the same for compatible WhereLoops. */
+    assert( p->rSetup==0 || pTemplate->rSetup==0 
+                 || p->rSetup==pTemplate->rSetup );
+
+    /* whereLoopAddBtree() always generates and inserts the automatic index
+    ** case first.  Hence compatible candidate WhereLoops never have a larger
+    ** rSetup. Call this SETUP-INVARIANT */
+    assert( p->rSetup>=pTemplate->rSetup );
+
+    /* Any loop using an appliation-defined index (or PRIMARY KEY or
+    ** UNIQUE constraint) with one or more == constraints is better
+    ** than an automatic index. Unless it is a skip-scan. */
+    if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
+     && (pTemplate->nSkip)==0
+     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+     && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
+     && (p->prereq & pTemplate->prereq)==pTemplate->prereq
+    ){
+      break;
+    }
+
+    /* If existing WhereLoop p is better than pTemplate, pTemplate can be
+    ** discarded.  WhereLoop p is better if:
+    **   (1)  p has no more dependencies than pTemplate, and
+    **   (2)  p has an equal or lower cost than pTemplate
+    */
+    if( (p->prereq & pTemplate->prereq)==p->prereq    /* (1)  */
+     && p->rSetup<=pTemplate->rSetup                  /* (2a) */
+     && p->rRun<=pTemplate->rRun                      /* (2b) */
+     && p->nOut<=pTemplate->nOut                      /* (2c) */
+    ){
+      return 0;  /* Discard pTemplate */
+    }
+
+    /* If pTemplate is always better than p, then cause p to be overwritten
+    ** with pTemplate.  pTemplate is better than p if:
+    **   (1)  pTemplate has no more dependences than p, and
+    **   (2)  pTemplate has an equal or lower cost than p.
+    */
+    if( (p->prereq & pTemplate->prereq)==pTemplate->prereq   /* (1)  */
+     && p->rRun>=pTemplate->rRun                             /* (2a) */
+     && p->nOut>=pTemplate->nOut                             /* (2b) */
+    ){
+      assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
+      break;   /* Cause p to be overwritten by pTemplate */
+    }
+  }
+  return ppPrev;
+}
+
+/*
+** Insert or replace a WhereLoop entry using the template supplied.
+**
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies.  Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template.  Otherwise a new WhereLoop is
+** added based on the template.
+**
+** If pBuilder->pOrSet is not NULL then we care about only the
+** prerequisites and rRun and nOut costs of the N best loops.  That
+** information is gathered in the pBuilder->pOrSet object.  This special
+** processing mode is used only for OR clause processing.
+**
+** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
+** still might overwrite similar loops with the new template if the
+** new template is better.  Loops may be overwritten if the following 
+** conditions are met:
+**
+**    (1)  They have the same iTab.
+**    (2)  They have the same iSortIdx.
+**    (3)  The template has same or fewer dependencies than the current loop
+**    (4)  The template has the same or lower cost than the current loop
+*/
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+  WhereLoop **ppPrev, *p;
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  sqlite3 *db = pWInfo->pParse->db;
+
+  /* If pBuilder->pOrSet is defined, then only keep track of the costs
+  ** and prereqs.
+  */
+  if( pBuilder->pOrSet!=0 ){
+    if( pTemplate->nLTerm ){
+#if WHERETRACE_ENABLED
+      u16 n = pBuilder->pOrSet->n;
+      int x =
+#endif
+      whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+                                    pTemplate->nOut);
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
+        whereLoopPrint(pTemplate, pBuilder->pWC);
+      }
+#endif
+    }
+    return SQLITE_OK;
+  }
+
+  /* Look for an existing WhereLoop to replace with pTemplate
+  */
+  whereLoopAdjustCost(pWInfo->pLoops, pTemplate);
+  ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
+
+  if( ppPrev==0 ){
+    /* There already exists a WhereLoop on the list that is better
+    ** than pTemplate, so just ignore pTemplate */
+#if WHERETRACE_ENABLED /* 0x8 */
+    if( sqlite3WhereTrace & 0x8 ){
+      sqlite3DebugPrintf("   skip: ");
+      whereLoopPrint(pTemplate, pBuilder->pWC);
+    }
+#endif
+    return SQLITE_OK;  
+  }else{
+    p = *ppPrev;
+  }
+
+  /* If we reach this point it means that either p[] should be overwritten
+  ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
+  ** WhereLoop and insert it.
+  */
+#if WHERETRACE_ENABLED /* 0x8 */
+  if( sqlite3WhereTrace & 0x8 ){
+    if( p!=0 ){
+      sqlite3DebugPrintf("replace: ");
+      whereLoopPrint(p, pBuilder->pWC);
+    }
+    sqlite3DebugPrintf("    add: ");
+    whereLoopPrint(pTemplate, pBuilder->pWC);
+  }
+#endif
+  if( p==0 ){
+    /* Allocate a new WhereLoop to add to the end of the list */
+    *ppPrev = p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
+    if( p==0 ) return SQLITE_NOMEM;
+    whereLoopInit(p);
+    p->pNextLoop = 0;
+  }else{
+    /* We will be overwriting WhereLoop p[].  But before we do, first
+    ** go through the rest of the list and delete any other entries besides
+    ** p[] that are also supplated by pTemplate */
+    WhereLoop **ppTail = &p->pNextLoop;
+    WhereLoop *pToDel;
+    while( *ppTail ){
+      ppTail = whereLoopFindLesser(ppTail, pTemplate);
+      if( ppTail==0 ) break;
+      pToDel = *ppTail;
+      if( pToDel==0 ) break;
+      *ppTail = pToDel->pNextLoop;
+#if WHERETRACE_ENABLED /* 0x8 */
+      if( sqlite3WhereTrace & 0x8 ){
+        sqlite3DebugPrintf(" delete: ");
+        whereLoopPrint(pToDel, pBuilder->pWC);
+      }
+#endif
+      whereLoopDelete(db, pToDel);
+    }
+  }
+  whereLoopXfer(db, p, pTemplate);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    Index *pIndex = p->u.btree.pIndex;
+    if( pIndex && pIndex->tnum==0 ){
+      p->u.btree.pIndex = 0;
+    }
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Adjust the WhereLoop.nOut value downward to account for terms of the
+** WHERE clause that reference the loop but which are not used by an
+** index.
+*
+** For every WHERE clause term that is not used by the index
+** and which has a truth probability assigned by one of the likelihood(),
+** likely(), or unlikely() SQL functions, reduce the estimated number
+** of output rows by the probability specified.
+**
+** TUNING:  For every WHERE clause term that is not used by the index
+** and which does not have an assigned truth probability, heuristics
+** described below are used to try to estimate the truth probability.
+** TODO --> Perhaps this is something that could be improved by better
+** table statistics.
+**
+** Heuristic 1:  Estimate the truth probability as 93.75%.  The 93.75%
+** value corresponds to -1 in LogEst notation, so this means decrement
+** the WhereLoop.nOut field for every such WHERE clause term.
+**
+** Heuristic 2:  If there exists one or more WHERE clause terms of the
+** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
+** final output row estimate is no greater than 1/4 of the total number
+** of rows in the table.  In other words, assume that x==EXPR will filter
+** out at least 3 out of 4 rows.  If EXPR is -1 or 0 or 1, then maybe the
+** "x" column is boolean or else -1 or 0 or 1 is a common default value
+** on the "x" column and so in that case only cap the output row estimate
+** at 1/2 instead of 1/4.
+*/
+static void whereLoopOutputAdjust(
+  WhereClause *pWC,      /* The WHERE clause */
+  WhereLoop *pLoop,      /* The loop to adjust downward */
+  LogEst nRow            /* Number of rows in the entire table */
+){
+  WhereTerm *pTerm, *pX;
+  Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
+  int i, j, k;
+  LogEst iReduce = 0;    /* pLoop->nOut should not exceed nRow-iReduce */
+
+  assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+  for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
+    if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
+    if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
+    if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
+    for(j=pLoop->nLTerm-1; j>=0; j--){
+      pX = pLoop->aLTerm[j];
+      if( pX==0 ) continue;
+      if( pX==pTerm ) break;
+      if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
+    }
+    if( j<0 ){
+      if( pTerm->truthProb<=0 ){
+        /* If a truth probability is specified using the likelihood() hints,
+        ** then use the probability provided by the application. */
+        pLoop->nOut += pTerm->truthProb;
+      }else{
+        /* In the absence of explicit truth probabilities, use heuristics to
+        ** guess a reasonable truth probability. */
+        pLoop->nOut--;
+        if( pTerm->eOperator&(WO_EQ|WO_IS) ){
+          Expr *pRight = pTerm->pExpr->pRight;
+          testcase( pTerm->pExpr->op==TK_IS );
+          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
+            k = 10;
+          }else{
+            k = 20;
+          }
+          if( iReduce<k ) iReduce = k;
+        }
+      }
+    }
+  }
+  if( pLoop->nOut > nRow-iReduce )  pLoop->nOut = nRow - iReduce;
+}
+
+/*
+** Adjust the cost C by the costMult facter T.  This only occurs if
+** compiled with -DSQLITE_ENABLE_COSTMULT
+*/
+#ifdef SQLITE_ENABLE_COSTMULT
+# define ApplyCostMultiplier(C,T)  C += T
+#else
+# define ApplyCostMultiplier(C,T)
+#endif
+
+/*
+** We have so far matched pBuilder->pNew->u.btree.nEq terms of the 
+** index pIndex. Try to match one more.
+**
+** When this function is called, pBuilder->pNew->nOut contains the 
+** number of rows expected to be visited by filtering using the nEq 
+** terms only. If it is modified, this value is restored before this 
+** function returns.
+**
+** If pProbe->tnum==0, that means pIndex is a fake index used for the
+** INTEGER PRIMARY KEY.
+*/
+static int whereLoopAddBtreeIndex(
+  WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */
+  struct SrcList_item *pSrc,      /* FROM clause term being analyzed */
+  Index *pProbe,                  /* An index on pSrc */
+  LogEst nInMul                   /* log(Number of iterations due to IN) */
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */
+  Parse *pParse = pWInfo->pParse;        /* Parsing context */
+  sqlite3 *db = pParse->db;       /* Database connection malloc context */
+  WhereLoop *pNew;                /* Template WhereLoop under construction */
+  WhereTerm *pTerm;               /* A WhereTerm under consideration */
+  int opMask;                     /* Valid operators for constraints */
+  WhereScan scan;                 /* Iterator for WHERE terms */
+  Bitmask saved_prereq;           /* Original value of pNew->prereq */
+  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
+  u16 saved_nEq;                  /* Original value of pNew->u.btree.nEq */
+  u16 saved_nSkip;                /* Original value of pNew->nSkip */
+  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
+  LogEst saved_nOut;              /* Original value of pNew->nOut */
+  int rc = SQLITE_OK;             /* Return code */
+  LogEst rSize;                   /* Number of rows in the table */
+  LogEst rLogSize;                /* Logarithm of table size */
+  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
+
+  pNew = pBuilder->pNew;
+  if( db->mallocFailed ) return SQLITE_NOMEM;
+
+  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
+  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
+    opMask = WO_LT|WO_LE;
+  }else if( /*pProbe->tnum<=0 ||*/ (pSrc->fg.jointype & JT_LEFT)!=0 ){
+    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
+  }else{
+    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
+  }
+  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+
+  assert( pNew->u.btree.nEq<pProbe->nColumn );
+
+  saved_nEq = pNew->u.btree.nEq;
+  saved_nSkip = pNew->nSkip;
+  saved_nLTerm = pNew->nLTerm;
+  saved_wsFlags = pNew->wsFlags;
+  saved_prereq = pNew->prereq;
+  saved_nOut = pNew->nOut;
+  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
+                        opMask, pProbe);
+  pNew->rSetup = 0;
+  rSize = pProbe->aiRowLogEst[0];
+  rLogSize = estLog(rSize);
+  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
+    u16 eOp = pTerm->eOperator;   /* Shorthand for pTerm->eOperator */
+    LogEst rCostIdx;
+    LogEst nOutUnadjusted;        /* nOut before IN() and WHERE adjustments */
+    int nIn = 0;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    int nRecValid = pBuilder->nRecValid;
+#endif
+    if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
+     && indexColumnNotNull(pProbe, saved_nEq)
+    ){
+      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
+    }
+    if( pTerm->prereqRight & pNew->maskSelf ) continue;
+
+    /* Do not allow the upper bound of a LIKE optimization range constraint
+    ** to mix with a lower range bound from some other source */
+    if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue;
+
+    pNew->wsFlags = saved_wsFlags;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nLTerm = saved_nLTerm;
+    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+    pNew->aLTerm[pNew->nLTerm++] = pTerm;
+    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
+
+    assert( nInMul==0
+        || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 
+        || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 
+        || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 
+    );
+
+    if( eOp & WO_IN ){
+      Expr *pExpr = pTerm->pExpr;
+      pNew->wsFlags |= WHERE_COLUMN_IN;
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
+        nIn = 46;  assert( 46==sqlite3LogEst(25) );
+      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
+        /* "x IN (value, value, ...)" */
+        nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
+      }
+      assert( nIn>0 );  /* RHS always has 2 or more terms...  The parser
+                        ** changes "x IN (?)" into "x=?". */
+
+    }else if( eOp & (WO_EQ|WO_IS) ){
+      int iCol = pProbe->aiColumn[saved_nEq];
+      pNew->wsFlags |= WHERE_COLUMN_EQ;
+      assert( saved_nEq==pNew->u.btree.nEq );
+      if( iCol==XN_ROWID 
+       || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
+      ){
+        if( iCol>=0 && pProbe->uniqNotNull==0 ){
+          pNew->wsFlags |= WHERE_UNQ_WANTED;
+        }else{
+          pNew->wsFlags |= WHERE_ONEROW;
+        }
+      }
+    }else if( eOp & WO_ISNULL ){
+      pNew->wsFlags |= WHERE_COLUMN_NULL;
+    }else if( eOp & (WO_GT|WO_GE) ){
+      testcase( eOp & WO_GT );
+      testcase( eOp & WO_GE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
+      pBtm = pTerm;
+      pTop = 0;
+      if( pTerm->wtFlags & TERM_LIKEOPT ){
+        /* Range contraints that come from the LIKE optimization are
+        ** always used in pairs. */
+        pTop = &pTerm[1];
+        assert( (pTop-(pTerm->pWC->a))<pTerm->pWC->nTerm );
+        assert( pTop->wtFlags & TERM_LIKEOPT );
+        assert( pTop->eOperator==WO_LT );
+        if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+        pNew->aLTerm[pNew->nLTerm++] = pTop;
+        pNew->wsFlags |= WHERE_TOP_LIMIT;
+      }
+    }else{
+      assert( eOp & (WO_LT|WO_LE) );
+      testcase( eOp & WO_LT );
+      testcase( eOp & WO_LE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
+      pTop = pTerm;
+      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
+                     pNew->aLTerm[pNew->nLTerm-2] : 0;
+    }
+
+    /* At this point pNew->nOut is set to the number of rows expected to
+    ** be visited by the index scan before considering term pTerm, or the
+    ** values of nIn and nInMul. In other words, assuming that all 
+    ** "x IN(...)" terms are replaced with "x = ?". This block updates
+    ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul).  */
+    assert( pNew->nOut==saved_nOut );
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4
+      ** data, using some other estimate.  */
+      whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
+    }else{
+      int nEq = ++pNew->u.btree.nEq;
+      assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );
+
+      assert( pNew->nOut==saved_nOut );
+      if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
+        assert( (eOp & WO_IN) || nIn==0 );
+        testcase( eOp & WO_IN );
+        pNew->nOut += pTerm->truthProb;
+        pNew->nOut -= nIn;
+      }else{
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+        tRowcnt nOut = 0;
+        if( nInMul==0 
+         && pProbe->nSample 
+         && pNew->u.btree.nEq<=pProbe->nSampleCol
+         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
+        ){
+          Expr *pExpr = pTerm->pExpr;
+          if( (eOp & (WO_EQ|WO_ISNULL|WO_IS))!=0 ){
+            testcase( eOp & WO_EQ );
+            testcase( eOp & WO_IS );
+            testcase( eOp & WO_ISNULL );
+            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
+          }else{
+            rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
+          }
+          if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+          if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */
+          if( nOut ){
+            pNew->nOut = sqlite3LogEst(nOut);
+            if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;
+            pNew->nOut -= nIn;
+          }
+        }
+        if( nOut==0 )
+#endif
+        {
+          pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);
+          if( eOp & WO_ISNULL ){
+            /* TUNING: If there is no likelihood() value, assume that a 
+            ** "col IS NULL" expression matches twice as many rows 
+            ** as (col=?). */
+            pNew->nOut += 10;
+          }
+        }
+      }
+    }
+
+    /* Set rCostIdx to the cost of visiting selected rows in index. Add
+    ** it to pNew->rRun, which is currently set to the cost of the index
+    ** seek only. Then, if this is a non-covering index, add the cost of
+    ** visiting the rows in the main table.  */
+    rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
+    pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
+    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+      pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
+    }
+    ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
+
+    nOutUnadjusted = pNew->nOut;
+    pNew->rRun += nInMul + nIn;
+    pNew->nOut += nInMul + nIn;
+    whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
+    rc = whereLoopInsert(pBuilder, pNew);
+
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      pNew->nOut = saved_nOut;
+    }else{
+      pNew->nOut = nOutUnadjusted;
+    }
+
+    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
+     && pNew->u.btree.nEq<pProbe->nColumn
+    ){
+      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
+    }
+    pNew->nOut = saved_nOut;
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    pBuilder->nRecValid = nRecValid;
+#endif
+  }
+  pNew->prereq = saved_prereq;
+  pNew->u.btree.nEq = saved_nEq;
+  pNew->nSkip = saved_nSkip;
+  pNew->wsFlags = saved_wsFlags;
+  pNew->nOut = saved_nOut;
+  pNew->nLTerm = saved_nLTerm;
+
+  /* Consider using a skip-scan if there are no WHERE clause constraints
+  ** available for the left-most terms of the index, and if the average
+  ** number of repeats in the left-most terms is at least 18. 
+  **
+  ** The magic number 18 is selected on the basis that scanning 17 rows
+  ** is almost always quicker than an index seek (even though if the index
+  ** contains fewer than 2^17 rows we assume otherwise in other parts of
+  ** the code). And, even if it is not, it should not be too much slower. 
+  ** On the other hand, the extra seeks could end up being significantly
+  ** more expensive.  */
+  assert( 42==sqlite3LogEst(18) );
+  if( saved_nEq==saved_nSkip
+   && saved_nEq+1<pProbe->nKeyCol
+   && pProbe->noSkipScan==0
+   && pProbe->aiRowLogEst[saved_nEq+1]>=42  /* TUNING: Minimum for skip-scan */
+   && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
+  ){
+    LogEst nIter;
+    pNew->u.btree.nEq++;
+    pNew->nSkip++;
+    pNew->aLTerm[pNew->nLTerm++] = 0;
+    pNew->wsFlags |= WHERE_SKIPSCAN;
+    nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
+    pNew->nOut -= nIter;
+    /* TUNING:  Because uncertainties in the estimates for skip-scan queries,
+    ** add a 1.375 fudge factor to make skip-scan slightly less likely. */
+    nIter += 5;
+    whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
+    pNew->nOut = saved_nOut;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nSkip = saved_nSkip;
+    pNew->wsFlags = saved_wsFlags;
+  }
+
+  return rc;
+}
+
+/*
+** Return True if it is possible that pIndex might be useful in
+** implementing the ORDER BY clause in pBuilder.
+**
+** Return False if pBuilder does not contain an ORDER BY clause or
+** if there is no way for pIndex to be useful in implementing that
+** ORDER BY clause.
+*/
+static int indexMightHelpWithOrderBy(
+  WhereLoopBuilder *pBuilder,
+  Index *pIndex,
+  int iCursor
+){
+  ExprList *pOB;
+  ExprList *aColExpr;
+  int ii, jj;
+
+  if( pIndex->bUnordered ) return 0;
+  if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
+  for(ii=0; ii<pOB->nExpr; ii++){
+    Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
+    if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
+      if( pExpr->iColumn<0 ) return 1;
+      for(jj=0; jj<pIndex->nKeyCol; jj++){
+        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
+      }
+    }else if( (aColExpr = pIndex->aColExpr)!=0 ){
+      for(jj=0; jj<pIndex->nKeyCol; jj++){
+        if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
+        if( sqlite3ExprCompare(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
+          return 1;
+        }
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Return a bitmask where 1s indicate that the corresponding column of
+** the table is used by an index.  Only the first 63 columns are considered.
+*/
+static Bitmask columnsInIndex(Index *pIdx){
+  Bitmask m = 0;
+  int j;
+  for(j=pIdx->nColumn-1; j>=0; j--){
+    int x = pIdx->aiColumn[j];
+    if( x>=0 ){
+      testcase( x==BMS-1 );
+      testcase( x==BMS-2 );
+      if( x<BMS-1 ) m |= MASKBIT(x);
+    }
+  }
+  return m;
+}
+
+/* Check to see if a partial index with pPartIndexWhere can be used
+** in the current query.  Return true if it can be and false if not.
+*/
+static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
+  int i;
+  WhereTerm *pTerm;
+  while( pWhere->op==TK_AND ){
+    if( !whereUsablePartialIndex(iTab,pWC,pWhere->pLeft) ) return 0;
+    pWhere = pWhere->pRight;
+  }
+  for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    Expr *pExpr = pTerm->pExpr;
+    if( sqlite3ExprImpliesExpr(pExpr, pWhere, iTab) 
+     && (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)
+    ){
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+** Add all WhereLoop objects for a single table of the join where the table
+** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be
+** a b-tree table, not a virtual table.
+**
+** The costs (WhereLoop.rRun) of the b-tree loops added by this function
+** are calculated as follows:
+**
+** For a full scan, assuming the table (or index) contains nRow rows:
+**
+**     cost = nRow * 3.0                    // full-table scan
+**     cost = nRow * K                      // scan of covering index
+**     cost = nRow * (K+3.0)                // scan of non-covering index
+**
+** where K is a value between 1.1 and 3.0 set based on the relative 
+** estimated average size of the index and table records.
+**
+** For an index scan, where nVisit is the number of index rows visited
+** by the scan, and nSeek is the number of seek operations required on 
+** the index b-tree:
+**
+**     cost = nSeek * (log(nRow) + K * nVisit)          // covering index
+**     cost = nSeek * (log(nRow) + (K+3.0) * nVisit)    // non-covering index
+**
+** Normally, nSeek is 1. nSeek values greater than 1 come about if the 
+** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when 
+** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.
+**
+** The estimated values (nRow, nVisit, nSeek) often contain a large amount
+** of uncertainty.  For this reason, scoring is designed to pick plans that
+** "do the least harm" if the estimates are inaccurate.  For example, a
+** log(nRow) factor is omitted from a non-covering index scan in order to
+** bias the scoring in favor of using an index, since the worst-case
+** performance of using an index is far better than the worst-case performance
+** of a full table scan.
+*/
+static int whereLoopAddBtree(
+  WhereLoopBuilder *pBuilder, /* WHERE clause information */
+  Bitmask mExtra              /* Extra prerequesites for using this table */
+){
+  WhereInfo *pWInfo;          /* WHERE analysis context */
+  Index *pProbe;              /* An index we are evaluating */
+  Index sPk;                  /* A fake index object for the primary key */
+  LogEst aiRowEstPk[2];       /* The aiRowLogEst[] value for the sPk index */
+  i16 aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
+  SrcList *pTabList;          /* The FROM clause */
+  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
+  WhereLoop *pNew;            /* Template WhereLoop object */
+  int rc = SQLITE_OK;         /* Return code */
+  int iSortIdx = 1;           /* Index number */
+  int b;                      /* A boolean value */
+  LogEst rSize;               /* number of rows in the table */
+  LogEst rLogSize;            /* Logarithm of the number of rows in the table */
+  WhereClause *pWC;           /* The parsed WHERE clause */
+  Table *pTab;                /* Table being queried */
+  
+  pNew = pBuilder->pNew;
+  pWInfo = pBuilder->pWInfo;
+  pTabList = pWInfo->pTabList;
+  pSrc = pTabList->a + pNew->iTab;
+  pTab = pSrc->pTab;
+  pWC = pBuilder->pWC;
+  assert( !IsVirtual(pSrc->pTab) );
+
+  if( pSrc->pIBIndex ){
+    /* An INDEXED BY clause specifies a particular index to use */
+    pProbe = pSrc->pIBIndex;
+  }else if( !HasRowid(pTab) ){
+    pProbe = pTab->pIndex;
+  }else{
+    /* There is no INDEXED BY clause.  Create a fake Index object in local
+    ** variable sPk to represent the rowid primary key index.  Make this
+    ** fake index the first in a chain of Index objects with all of the real
+    ** indices to follow */
+    Index *pFirst;                  /* First of real indices on the table */
+    memset(&sPk, 0, sizeof(Index));
+    sPk.nKeyCol = 1;
+    sPk.nColumn = 1;
+    sPk.aiColumn = &aiColumnPk;
+    sPk.aiRowLogEst = aiRowEstPk;
+    sPk.onError = OE_Replace;
+    sPk.pTable = pTab;
+    sPk.szIdxRow = pTab->szTabRow;
+    aiRowEstPk[0] = pTab->nRowLogEst;
+    aiRowEstPk[1] = 0;
+    pFirst = pSrc->pTab->pIndex;
+    if( pSrc->fg.notIndexed==0 ){
+      /* The real indices of the table are only considered if the
+      ** NOT INDEXED qualifier is omitted from the FROM clause */
+      sPk.pNext = pFirst;
+    }
+    pProbe = &sPk;
+  }
+  rSize = pTab->nRowLogEst;
+  rLogSize = estLog(rSize);
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+  /* Automatic indexes */
+  if( !pBuilder->pOrSet      /* Not part of an OR optimization */
+   && (pWInfo->wctrlFlags & WHERE_NO_AUTOINDEX)==0
+   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
+   && pSrc->pIBIndex==0      /* Has no INDEXED BY clause */
+   && !pSrc->fg.notIndexed   /* Has no NOT INDEXED clause */
+   && HasRowid(pTab)         /* Not WITHOUT ROWID table. (FIXME: Why not?) */
+   && !pSrc->fg.isCorrelated /* Not a correlated subquery */
+   && !pSrc->fg.isRecursive  /* Not a recursive common table expression. */
+  ){
+    /* Generate auto-index WhereLoops */
+    WhereTerm *pTerm;
+    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
+    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
+      if( pTerm->prereqRight & pNew->maskSelf ) continue;
+      if( termCanDriveIndex(pTerm, pSrc, 0) ){
+        pNew->u.btree.nEq = 1;
+        pNew->nSkip = 0;
+        pNew->u.btree.pIndex = 0;
+        pNew->nLTerm = 1;
+        pNew->aLTerm[0] = pTerm;
+        /* TUNING: One-time cost for computing the automatic index is
+        ** estimated to be X*N*log2(N) where N is the number of rows in
+        ** the table being indexed and where X is 7 (LogEst=28) for normal
+        ** tables or 1.375 (LogEst=4) for views and subqueries.  The value
+        ** of X is smaller for views and subqueries so that the query planner
+        ** will be more aggressive about generating automatic indexes for
+        ** those objects, since there is no opportunity to add schema
+        ** indexes on subqueries and views. */
+        pNew->rSetup = rLogSize + rSize + 4;
+        if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){
+          pNew->rSetup += 24;
+        }
+        ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
+        /* TUNING: Each index lookup yields 20 rows in the table.  This
+        ** is more than the usual guess of 10 rows, since we have no way
+        ** of knowing how selective the index will ultimately be.  It would
+        ** not be unreasonable to make this value much larger. */
+        pNew->nOut = 43;  assert( 43==sqlite3LogEst(20) );
+        pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
+        pNew->wsFlags = WHERE_AUTO_INDEX;
+        pNew->prereq = mExtra | pTerm->prereqRight;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+    }
+  }
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+  /* Loop over all indices
+  */
+  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
+    if( pProbe->pPartIdxWhere!=0
+     && !whereUsablePartialIndex(pSrc->iCursor, pWC, pProbe->pPartIdxWhere) ){
+      testcase( pNew->iTab!=pSrc->iCursor );  /* See ticket [98d973b8f5] */
+      continue;  /* Partial index inappropriate for this query */
+    }
+    rSize = pProbe->aiRowLogEst[0];
+    pNew->u.btree.nEq = 0;
+    pNew->nSkip = 0;
+    pNew->nLTerm = 0;
+    pNew->iSortIdx = 0;
+    pNew->rSetup = 0;
+    pNew->prereq = mExtra;
+    pNew->nOut = rSize;
+    pNew->u.btree.pIndex = pProbe;
+    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
+    if( pProbe->tnum<=0 ){
+      /* Integer primary key index */
+      pNew->wsFlags = WHERE_IPK;
+
+      /* Full table scan */
+      pNew->iSortIdx = b ? iSortIdx : 0;
+      /* TUNING: Cost of full table scan is (N*3.0). */
+      pNew->rRun = rSize + 16;
+      ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+      whereLoopOutputAdjust(pWC, pNew, rSize);
+      rc = whereLoopInsert(pBuilder, pNew);
+      pNew->nOut = rSize;
+      if( rc ) break;
+    }else{
+      Bitmask m;
+      if( pProbe->isCovering ){
+        pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
+        m = 0;
+      }else{
+        m = pSrc->colUsed & ~columnsInIndex(pProbe);
+        pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
+      }
+
+      /* Full scan via index */
+      if( b
+       || !HasRowid(pTab)
+       || ( m==0
+         && pProbe->bUnordered==0
+         && (pProbe->szIdxRow<pTab->szTabRow)
+         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+         && sqlite3GlobalConfig.bUseCis
+         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+          )
+      ){
+        pNew->iSortIdx = b ? iSortIdx : 0;
+
+        /* The cost of visiting the index rows is N*K, where K is
+        ** between 1.1 and 3.0, depending on the relative sizes of the
+        ** index and table rows. If this is a non-covering index scan,
+        ** also add the cost of visiting table rows (N*3.0).  */
+        pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
+        if( m!=0 ){
+          pNew->rRun = sqlite3LogEstAdd(pNew->rRun, rSize+16);
+        }
+        ApplyCostMultiplier(pNew->rRun, pTab->costMult);
+        whereLoopOutputAdjust(pWC, pNew, rSize);
+        rc = whereLoopInsert(pBuilder, pNew);
+        pNew->nOut = rSize;
+        if( rc ) break;
+      }
+    }
+
+    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
+#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
+    sqlite3Stat4ProbeFree(pBuilder->pRec);
+    pBuilder->nRecValid = 0;
+    pBuilder->pRec = 0;
+#endif
+
+    /* If there was an INDEXED BY clause, then only that one index is
+    ** considered. */
+    if( pSrc->pIBIndex ) break;
+  }
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Add all WhereLoop objects for a table of the join identified by
+** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
+**
+** If there are no LEFT or CROSS JOIN joins in the query, both mExtra and
+** mUnusable are set to 0. Otherwise, mExtra is a mask of all FROM clause
+** entries that occur before the virtual table in the FROM clause and are
+** separated from it by at least one LEFT or CROSS JOIN. Similarly, the
+** mUnusable mask contains all FROM clause entries that occur after the
+** virtual table and are separated from it by at least one LEFT or 
+** CROSS JOIN. 
+**
+** For example, if the query were:
+**
+**   ... FROM t1, t2 LEFT JOIN t3, t4, vt CROSS JOIN t5, t6;
+**
+** then mExtra corresponds to (t1, t2) and mUnusable to (t5, t6).
+**
+** All the tables in mExtra must be scanned before the current virtual 
+** table. So any terms for which all prerequisites are satisfied by 
+** mExtra may be specified as "usable" in all calls to xBestIndex. 
+** Conversely, all tables in mUnusable must be scanned after the current
+** virtual table, so any terms for which the prerequisites overlap with
+** mUnusable should always be configured as "not-usable" for xBestIndex.
+*/
+static int whereLoopAddVirtual(
+  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
+  Bitmask mExtra,              /* Tables that must be scanned before this one */
+  Bitmask mUnusable            /* Tables that must be scanned after this one */
+){
+  WhereInfo *pWInfo;           /* WHERE analysis context */
+  Parse *pParse;               /* The parsing context */
+  WhereClause *pWC;            /* The WHERE clause */
+  struct SrcList_item *pSrc;   /* The FROM clause term to search */
+  Table *pTab;
+  sqlite3 *db;
+  sqlite3_index_info *pIdxInfo;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_constraint_usage *pUsage;
+  WhereTerm *pTerm;
+  int i, j;
+  int iTerm, mxTerm;
+  int nConstraint;
+  int seenIn = 0;              /* True if an IN operator is seen */
+  int seenVar = 0;             /* True if a non-constant constraint is seen */
+  int iPhase;                  /* 0: const w/o IN, 1: const, 2: no IN,  2: IN */
+  WhereLoop *pNew;
+  int rc = SQLITE_OK;
+
+  assert( (mExtra & mUnusable)==0 );
+  pWInfo = pBuilder->pWInfo;
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  pWC = pBuilder->pWC;
+  pNew = pBuilder->pNew;
+  pSrc = &pWInfo->pTabList->a[pNew->iTab];
+  pTab = pSrc->pTab;
+  assert( IsVirtual(pTab) );
+  pIdxInfo = allocateIndexInfo(pParse, pWC, mUnusable, pSrc,pBuilder->pOrderBy);
+  if( pIdxInfo==0 ) return SQLITE_NOMEM;
+  pNew->prereq = 0;
+  pNew->rSetup = 0;
+  pNew->wsFlags = WHERE_VIRTUALTABLE;
+  pNew->nLTerm = 0;
+  pNew->u.vtab.needFree = 0;
+  pUsage = pIdxInfo->aConstraintUsage;
+  nConstraint = pIdxInfo->nConstraint;
+  if( whereLoopResize(db, pNew, nConstraint) ){
+    sqlite3DbFree(db, pIdxInfo);
+    return SQLITE_NOMEM;
+  }
+
+  for(iPhase=0; iPhase<=3; iPhase++){
+    if( !seenIn && (iPhase&1)!=0 ){
+      iPhase++;
+      if( iPhase>3 ) break;
+    }
+    if( !seenVar && iPhase>1 ) break;
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+      j = pIdxCons->iTermOffset;
+      pTerm = &pWC->a[j];
+      switch( iPhase ){
+        case 0:    /* Constants without IN operator */
+          pIdxCons->usable = 0;
+          if( (pTerm->eOperator & WO_IN)!=0 ){
+            seenIn = 1;
+          }
+          if( (pTerm->prereqRight & ~mExtra)!=0 ){
+            seenVar = 1;
+          }else if( (pTerm->eOperator & WO_IN)==0 ){
+            pIdxCons->usable = 1;
+          }
+          break;
+        case 1:    /* Constants with IN operators */
+          assert( seenIn );
+          pIdxCons->usable = (pTerm->prereqRight & ~mExtra)==0;
+          break;
+        case 2:    /* Variables without IN */
+          assert( seenVar );
+          pIdxCons->usable = (pTerm->eOperator & WO_IN)==0;
+          break;
+        default:   /* Variables with IN */
+          assert( seenVar && seenIn );
+          pIdxCons->usable = 1;
+          break;
+      }
+    }
+    memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
+    if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+    pIdxInfo->idxStr = 0;
+    pIdxInfo->idxNum = 0;
+    pIdxInfo->needToFreeIdxStr = 0;
+    pIdxInfo->orderByConsumed = 0;
+    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
+    pIdxInfo->estimatedRows = 25;
+    pIdxInfo->idxFlags = 0;
+    pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;
+    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
+    if( rc ) goto whereLoopAddVtab_exit;
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    pNew->prereq = mExtra;
+    mxTerm = -1;
+    assert( pNew->nLSlot>=nConstraint );
+    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
+    pNew->u.vtab.omitMask = 0;
+    for(i=0; i<nConstraint; i++, pIdxCons++){
+      if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
+        j = pIdxCons->iTermOffset;
+        if( iTerm>=nConstraint
+         || j<0
+         || j>=pWC->nTerm
+         || pNew->aLTerm[iTerm]!=0
+        ){
+          rc = SQLITE_ERROR;
+          sqlite3ErrorMsg(pParse, "%s.xBestIndex() malfunction", pTab->zName);
+          goto whereLoopAddVtab_exit;
+        }
+        testcase( iTerm==nConstraint-1 );
+        testcase( j==0 );
+        testcase( j==pWC->nTerm-1 );
+        pTerm = &pWC->a[j];
+        pNew->prereq |= pTerm->prereqRight;
+        assert( iTerm<pNew->nLSlot );
+        pNew->aLTerm[iTerm] = pTerm;
+        if( iTerm>mxTerm ) mxTerm = iTerm;
+        testcase( iTerm==15 );
+        testcase( iTerm==16 );
+        if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm;
+        if( (pTerm->eOperator & WO_IN)!=0 ){
+          if( pUsage[i].omit==0 ){
+            /* Do not attempt to use an IN constraint if the virtual table
+            ** says that the equivalent EQ constraint cannot be safely omitted.
+            ** If we do attempt to use such a constraint, some rows might be
+            ** repeated in the output. */
+            break;
+          }
+          /* A virtual table that is constrained by an IN clause may not
+          ** consume the ORDER BY clause because (1) the order of IN terms
+          ** is not necessarily related to the order of output terms and
+          ** (2) Multiple outputs from a single IN value will not merge
+          ** together.  */
+          pIdxInfo->orderByConsumed = 0;
+          pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
+        }
+      }
+    }
+    if( i>=nConstraint ){
+      pNew->nLTerm = mxTerm+1;
+      assert( pNew->nLTerm<=pNew->nLSlot );
+      pNew->u.vtab.idxNum = pIdxInfo->idxNum;
+      pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
+      pIdxInfo->needToFreeIdxStr = 0;
+      pNew->u.vtab.idxStr = pIdxInfo->idxStr;
+      pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
+                                      pIdxInfo->nOrderBy : 0);
+      pNew->rSetup = 0;
+      pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
+      pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);
+
+      /* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
+      ** that the scan will visit at most one row. Clear it otherwise. */
+      if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){
+        pNew->wsFlags |= WHERE_ONEROW;
+      }else{
+        pNew->wsFlags &= ~WHERE_ONEROW;
+      }
+      whereLoopInsert(pBuilder, pNew);
+      if( pNew->u.vtab.needFree ){
+        sqlite3_free(pNew->u.vtab.idxStr);
+        pNew->u.vtab.needFree = 0;
+      }
+    }
+  }  
+
+whereLoopAddVtab_exit:
+  if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+  sqlite3DbFree(db, pIdxInfo);
+  return rc;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Add WhereLoop entries to handle OR terms.  This works for either
+** btrees or virtual tables.
+*/
+static int whereLoopAddOr(
+  WhereLoopBuilder *pBuilder, 
+  Bitmask mExtra, 
+  Bitmask mUnusable
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  WhereClause *pWC;
+  WhereLoop *pNew;
+  WhereTerm *pTerm, *pWCEnd;
+  int rc = SQLITE_OK;
+  int iCur;
+  WhereClause tempWC;
+  WhereLoopBuilder sSubBuild;
+  WhereOrSet sSum, sCur;
+  struct SrcList_item *pItem;
+  
+  pWC = pBuilder->pWC;
+  pWCEnd = pWC->a + pWC->nTerm;
+  pNew = pBuilder->pNew;
+  memset(&sSum, 0, sizeof(sSum));
+  pItem = pWInfo->pTabList->a + pNew->iTab;
+  iCur = pItem->iCursor;
+
+  for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){
+    if( (pTerm->eOperator & WO_OR)!=0
+     && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 
+    ){
+      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
+      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
+      WhereTerm *pOrTerm;
+      int once = 1;
+      int i, j;
+    
+      sSubBuild = *pBuilder;
+      sSubBuild.pOrderBy = 0;
+      sSubBuild.pOrSet = &sCur;
+
+      WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));
+      for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
+        if( (pOrTerm->eOperator & WO_AND)!=0 ){
+          sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
+        }else if( pOrTerm->leftCursor==iCur ){
+          tempWC.pWInfo = pWC->pWInfo;
+          tempWC.pOuter = pWC;
+          tempWC.op = TK_AND;
+          tempWC.nTerm = 1;
+          tempWC.a = pOrTerm;
+          sSubBuild.pWC = &tempWC;
+        }else{
+          continue;
+        }
+        sCur.n = 0;
+#ifdef WHERETRACE_ENABLED
+        WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n", 
+                   (int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
+        if( sqlite3WhereTrace & 0x400 ){
+          for(i=0; i<sSubBuild.pWC->nTerm; i++){
+            whereTermPrint(&sSubBuild.pWC->a[i], i);
+          }
+        }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+        if( IsVirtual(pItem->pTab) ){
+          rc = whereLoopAddVirtual(&sSubBuild, mExtra, mUnusable);
+        }else
+#endif
+        {
+          rc = whereLoopAddBtree(&sSubBuild, mExtra);
+        }
+        if( rc==SQLITE_OK ){
+          rc = whereLoopAddOr(&sSubBuild, mExtra, mUnusable);
+        }
+        assert( rc==SQLITE_OK || sCur.n==0 );
+        if( sCur.n==0 ){
+          sSum.n = 0;
+          break;
+        }else if( once ){
+          whereOrMove(&sSum, &sCur);
+          once = 0;
+        }else{
+          WhereOrSet sPrev;
+          whereOrMove(&sPrev, &sSum);
+          sSum.n = 0;
+          for(i=0; i<sPrev.n; i++){
+            for(j=0; j<sCur.n; j++){
+              whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq,
+                            sqlite3LogEstAdd(sPrev.a[i].rRun, sCur.a[j].rRun),
+                            sqlite3LogEstAdd(sPrev.a[i].nOut, sCur.a[j].nOut));
+            }
+          }
+        }
+      }
+      pNew->nLTerm = 1;
+      pNew->aLTerm[0] = pTerm;
+      pNew->wsFlags = WHERE_MULTI_OR;
+      pNew->rSetup = 0;
+      pNew->iSortIdx = 0;
+      memset(&pNew->u, 0, sizeof(pNew->u));
+      for(i=0; rc==SQLITE_OK && i<sSum.n; i++){
+        /* TUNING: Currently sSum.a[i].rRun is set to the sum of the costs
+        ** of all sub-scans required by the OR-scan. However, due to rounding
+        ** errors, it may be that the cost of the OR-scan is equal to its
+        ** most expensive sub-scan. Add the smallest possible penalty 
+        ** (equivalent to multiplying the cost by 1.07) to ensure that 
+        ** this does not happen. Otherwise, for WHERE clauses such as the
+        ** following where there is an index on "y":
+        **
+        **     WHERE likelihood(x=?, 0.99) OR y=?
+        **
+        ** the planner may elect to "OR" together a full-table scan and an
+        ** index lookup. And other similarly odd results.  */
+        pNew->rRun = sSum.a[i].rRun + 1;
+        pNew->nOut = sSum.a[i].nOut;
+        pNew->prereq = sSum.a[i].prereq;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+      WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));
+    }
+  }
+  return rc;
+}
+
+/*
+** Add all WhereLoop objects for all tables 
+*/
+static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  Bitmask mExtra = 0;
+  Bitmask mPrior = 0;
+  int iTab;
+  SrcList *pTabList = pWInfo->pTabList;
+  struct SrcList_item *pItem;
+  struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];
+  sqlite3 *db = pWInfo->pParse->db;
+  int rc = SQLITE_OK;
+  WhereLoop *pNew;
+  u8 priorJointype = 0;
+
+  /* Loop over the tables in the join, from left to right */
+  pNew = pBuilder->pNew;
+  whereLoopInit(pNew);
+  for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
+    Bitmask mUnusable = 0;
+    pNew->iTab = iTab;
+    pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
+    if( ((pItem->fg.jointype|priorJointype) & (JT_LEFT|JT_CROSS))!=0 ){
+      /* This condition is true when pItem is the FROM clause term on the
+      ** right-hand-side of a LEFT or CROSS JOIN.  */
+      mExtra = mPrior;
+    }
+    priorJointype = pItem->fg.jointype;
+    if( IsVirtual(pItem->pTab) ){
+      struct SrcList_item *p;
+      for(p=&pItem[1]; p<pEnd; p++){
+        if( mUnusable || (p->fg.jointype & (JT_LEFT|JT_CROSS)) ){
+          mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
+        }
+      }
+      rc = whereLoopAddVirtual(pBuilder, mExtra, mUnusable);
+    }else{
+      rc = whereLoopAddBtree(pBuilder, mExtra);
+    }
+    if( rc==SQLITE_OK ){
+      rc = whereLoopAddOr(pBuilder, mExtra, mUnusable);
+    }
+    mPrior |= pNew->maskSelf;
+    if( rc || db->mallocFailed ) break;
+  }
+
+  whereLoopClear(db, pNew);
+  return rc;
+}
+
+/*
+** Examine a WherePath (with the addition of the extra WhereLoop of the 5th
+** parameters) to see if it outputs rows in the requested ORDER BY
+** (or GROUP BY) without requiring a separate sort operation.  Return N:
+** 
+**   N>0:   N terms of the ORDER BY clause are satisfied
+**   N==0:  No terms of the ORDER BY clause are satisfied
+**   N<0:   Unknown yet how many terms of ORDER BY might be satisfied.   
+**
+** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
+** strict.  With GROUP BY and DISTINCT the only requirement is that
+** equivalent rows appear immediately adjacent to one another.  GROUP BY
+** and DISTINCT do not require rows to appear in any particular order as long
+** as equivalent rows are grouped together.  Thus for GROUP BY and DISTINCT
+** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
+** pOrderBy terms must be matched in strict left-to-right order.
+*/
+static i8 wherePathSatisfiesOrderBy(
+  WhereInfo *pWInfo,    /* The WHERE clause */
+  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
+  WherePath *pPath,     /* The WherePath to check */
+  u16 wctrlFlags,       /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */
+  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
+  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
+  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
+){
+  u8 revSet;            /* True if rev is known */
+  u8 rev;               /* Composite sort order */
+  u8 revIdx;            /* Index sort order */
+  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
+  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
+  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
+  u16 nKeyCol;          /* Number of key columns in pIndex */
+  u16 nColumn;          /* Total number of ordered columns in the index */
+  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
+  int iLoop;            /* Index of WhereLoop in pPath being processed */
+  int i, j;             /* Loop counters */
+  int iCur;             /* Cursor number for current WhereLoop */
+  int iColumn;          /* A column number within table iCur */
+  WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
+  WhereTerm *pTerm;     /* A single term of the WHERE clause */
+  Expr *pOBExpr;        /* An expression from the ORDER BY clause */
+  CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */
+  Index *pIndex;        /* The index associated with pLoop */
+  sqlite3 *db = pWInfo->pParse->db;  /* Database connection */
+  Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */
+  Bitmask obDone;       /* Mask of all ORDER BY terms */
+  Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */
+  Bitmask ready;              /* Mask of inner loops */
+
+  /*
+  ** We say the WhereLoop is "one-row" if it generates no more than one
+  ** row of output.  A WhereLoop is one-row if all of the following are true:
+  **  (a) All index columns match with WHERE_COLUMN_EQ.
+  **  (b) The index is unique
+  ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
+  ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
+  **
+  ** We say the WhereLoop is "order-distinct" if the set of columns from
+  ** that WhereLoop that are in the ORDER BY clause are different for every
+  ** row of the WhereLoop.  Every one-row WhereLoop is automatically
+  ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause
+  ** is not order-distinct. To be order-distinct is not quite the same as being
+  ** UNIQUE since a UNIQUE column or index can have multiple rows that 
+  ** are NULL and NULL values are equivalent for the purpose of order-distinct.
+  ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
+  **
+  ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
+  ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
+  ** automatically order-distinct.
+  */
+
+  assert( pOrderBy!=0 );
+  if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+
+  nOrderBy = pOrderBy->nExpr;
+  testcase( nOrderBy==BMS-1 );
+  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
+  isOrderDistinct = 1;
+  obDone = MASKBIT(nOrderBy)-1;
+  orderDistinctMask = 0;
+  ready = 0;
+  for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
+    if( iLoop>0 ) ready |= pLoop->maskSelf;
+    pLoop = iLoop<nLoop ? pPath->aLoop[iLoop] : pLast;
+    if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
+      if( pLoop->u.vtab.isOrdered ) obSat = obDone;
+      break;
+    }
+    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
+
+    /* Mark off any ORDER BY term X that is a column in the table of
+    ** the current loop for which there is term in the WHERE
+    ** clause of the form X IS NULL or X=? that reference only outer
+    ** loops.
+    */
+    for(i=0; i<nOrderBy; i++){
+      if( MASKBIT(i) & obSat ) continue;
+      pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+      if( pOBExpr->op!=TK_COLUMN ) continue;
+      if( pOBExpr->iTable!=iCur ) continue;
+      pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+                       ~ready, WO_EQ|WO_ISNULL|WO_IS, 0);
+      if( pTerm==0 ) continue;
+      if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
+        const char *z1, *z2;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z1 = pColl->zName;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z2 = pColl->zName;
+        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+        testcase( pTerm->pExpr->op==TK_IS );
+      }
+      obSat |= MASKBIT(i);
+    }
+
+    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
+      if( pLoop->wsFlags & WHERE_IPK ){
+        pIndex = 0;
+        nKeyCol = 0;
+        nColumn = 1;
+      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
+        return 0;
+      }else{
+        nKeyCol = pIndex->nKeyCol;
+        nColumn = pIndex->nColumn;
+        assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
+        assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
+                          || !HasRowid(pIndex->pTable));
+        isOrderDistinct = IsUniqueIndex(pIndex);
+      }
+
+      /* Loop through all columns of the index and deal with the ones
+      ** that are not constrained by == or IN.
+      */
+      rev = revSet = 0;
+      distinctColumns = 0;
+      for(j=0; j<nColumn; j++){
+        u8 bOnce;   /* True to run the ORDER BY search loop */
+
+        /* Skip over == and IS NULL terms */
+        if( j<pLoop->u.btree.nEq
+         && pLoop->nSkip==0
+         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL|WO_IS))!=0
+        ){
+          if( i & WO_ISNULL ){
+            testcase( isOrderDistinct );
+            isOrderDistinct = 0;
+          }
+          continue;  
+        }
+
+        /* Get the column number in the table (iColumn) and sort order
+        ** (revIdx) for the j-th column of the index.
+        */
+        if( pIndex ){
+          iColumn = pIndex->aiColumn[j];
+          revIdx = pIndex->aSortOrder[j];
+          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
+        }else{
+          iColumn = XN_ROWID;
+          revIdx = 0;
+        }
+
+        /* An unconstrained column that might be NULL means that this
+        ** WhereLoop is not well-ordered
+        */
+        if( isOrderDistinct
+         && iColumn>=0
+         && j>=pLoop->u.btree.nEq
+         && pIndex->pTable->aCol[iColumn].notNull==0
+        ){
+          isOrderDistinct = 0;
+        }
+
+        /* Find the ORDER BY term that corresponds to the j-th column
+        ** of the index and mark that ORDER BY term off 
+        */
+        bOnce = 1;
+        isMatch = 0;
+        for(i=0; bOnce && i<nOrderBy; i++){
+          if( MASKBIT(i) & obSat ) continue;
+          pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+          testcase( wctrlFlags & WHERE_GROUPBY );
+          testcase( wctrlFlags & WHERE_DISTINCTBY );
+          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
+          if( iColumn>=(-1) ){
+            if( pOBExpr->op!=TK_COLUMN ) continue;
+            if( pOBExpr->iTable!=iCur ) continue;
+            if( pOBExpr->iColumn!=iColumn ) continue;
+          }else{
+            if( sqlite3ExprCompare(pOBExpr,pIndex->aColExpr->a[j].pExpr,iCur) ){
+              continue;
+            }
+          }
+          if( iColumn>=0 ){
+            pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+            if( !pColl ) pColl = db->pDfltColl;
+            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
+          }
+          isMatch = 1;
+          break;
+        }
+        if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
+          /* Make sure the sort order is compatible in an ORDER BY clause.
+          ** Sort order is irrelevant for a GROUP BY clause. */
+          if( revSet ){
+            if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0;
+          }else{
+            rev = revIdx ^ pOrderBy->a[i].sortOrder;
+            if( rev ) *pRevMask |= MASKBIT(iLoop);
+            revSet = 1;
+          }
+        }
+        if( isMatch ){
+          if( iColumn<0 ){
+            testcase( distinctColumns==0 );
+            distinctColumns = 1;
+          }
+          obSat |= MASKBIT(i);
+        }else{
+          /* No match found */
+          if( j==0 || j<nKeyCol ){
+            testcase( isOrderDistinct!=0 );
+            isOrderDistinct = 0;
+          }
+          break;
+        }
+      } /* end Loop over all index columns */
+      if( distinctColumns ){
+        testcase( isOrderDistinct==0 );
+        isOrderDistinct = 1;
+      }
+    } /* end-if not one-row */
+
+    /* Mark off any other ORDER BY terms that reference pLoop */
+    if( isOrderDistinct ){
+      orderDistinctMask |= pLoop->maskSelf;
+      for(i=0; i<nOrderBy; i++){
+        Expr *p;
+        Bitmask mTerm;
+        if( MASKBIT(i) & obSat ) continue;
+        p = pOrderBy->a[i].pExpr;
+        mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);
+        if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
+        if( (mTerm&~orderDistinctMask)==0 ){
+          obSat |= MASKBIT(i);
+        }
+      }
+    }
+  } /* End the loop over all WhereLoops from outer-most down to inner-most */
+  if( obSat==obDone ) return (i8)nOrderBy;
+  if( !isOrderDistinct ){
+    for(i=nOrderBy-1; i>0; i--){
+      Bitmask m = MASKBIT(i) - 1;
+      if( (obSat&m)==m ) return i;
+    }
+    return 0;
+  }
+  return -1;
+}
+
+
+/*
+** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),
+** the planner assumes that the specified pOrderBy list is actually a GROUP
+** BY clause - and so any order that groups rows as required satisfies the
+** request.
+**
+** Normally, in this case it is not possible for the caller to determine
+** whether or not the rows are really being delivered in sorted order, or
+** just in some other order that provides the required grouping. However,
+** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then
+** this function may be called on the returned WhereInfo object. It returns
+** true if the rows really will be sorted in the specified order, or false
+** otherwise.
+**
+** For example, assuming:
+**
+**   CREATE INDEX i1 ON t1(x, Y);
+**
+** then
+**
+**   SELECT * FROM t1 GROUP BY x,y ORDER BY x,y;   -- IsSorted()==1
+**   SELECT * FROM t1 GROUP BY y,x ORDER BY y,x;   -- IsSorted()==0
+*/
+SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){
+  assert( pWInfo->wctrlFlags & WHERE_GROUPBY );
+  assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );
+  return pWInfo->sorted;
+}
+
+#ifdef WHERETRACE_ENABLED
+/* For debugging use only: */
+static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
+  static char zName[65];
+  int i;
+  for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }
+  if( pLast ) zName[i++] = pLast->cId;
+  zName[i] = 0;
+  return zName;
+}
+#endif
+
+/*
+** Return the cost of sorting nRow rows, assuming that the keys have 
+** nOrderby columns and that the first nSorted columns are already in
+** order.
+*/
+static LogEst whereSortingCost(
+  WhereInfo *pWInfo,
+  LogEst nRow,
+  int nOrderBy,
+  int nSorted
+){
+  /* TUNING: Estimated cost of a full external sort, where N is 
+  ** the number of rows to sort is:
+  **
+  **   cost = (3.0 * N * log(N)).
+  ** 
+  ** Or, if the order-by clause has X terms but only the last Y 
+  ** terms are out of order, then block-sorting will reduce the 
+  ** sorting cost to:
+  **
+  **   cost = (3.0 * N * log(N)) * (Y/X)
+  **
+  ** The (Y/X) term is implemented using stack variable rScale
+  ** below.  */
+  LogEst rScale, rSortCost;
+  assert( nOrderBy>0 && 66==sqlite3LogEst(100) );
+  rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66;
+  rSortCost = nRow + estLog(nRow) + rScale + 16;
+
+  /* TUNING: The cost of implementing DISTINCT using a B-TREE is
+  ** similar but with a larger constant of proportionality. 
+  ** Multiply by an additional factor of 3.0.  */
+  if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+    rSortCost += 16;
+  }
+
+  return rSortCost;
+}
+
+/*
+** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
+** attempts to find the lowest cost path that visits each WhereLoop
+** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
+**
+** Assume that the total number of output rows that will need to be sorted
+** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting
+** costs if nRowEst==0.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
+** error occurs.
+*/
+static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
+  int mxChoice;             /* Maximum number of simultaneous paths tracked */
+  int nLoop;                /* Number of terms in the join */
+  Parse *pParse;            /* Parsing context */
+  sqlite3 *db;              /* The database connection */
+  int iLoop;                /* Loop counter over the terms of the join */
+  int ii, jj;               /* Loop counters */
+  int mxI = 0;              /* Index of next entry to replace */
+  int nOrderBy;             /* Number of ORDER BY clause terms */
+  LogEst mxCost = 0;        /* Maximum cost of a set of paths */
+  LogEst mxUnsorted = 0;    /* Maximum unsorted cost of a set of path */
+  int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
+  WherePath *aFrom;         /* All nFrom paths at the previous level */
+  WherePath *aTo;           /* The nTo best paths at the current level */
+  WherePath *pFrom;         /* An element of aFrom[] that we are working on */
+  WherePath *pTo;           /* An element of aTo[] that we are working on */
+  WhereLoop *pWLoop;        /* One of the WhereLoop objects */
+  WhereLoop **pX;           /* Used to divy up the pSpace memory */
+  LogEst *aSortCost = 0;    /* Sorting and partial sorting costs */
+  char *pSpace;             /* Temporary memory used by this routine */
+  int nSpace;               /* Bytes of space allocated at pSpace */
+
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  nLoop = pWInfo->nLevel;
+  /* TUNING: For simple queries, only the best path is tracked.
+  ** For 2-way joins, the 5 best paths are followed.
+  ** For joins of 3 or more tables, track the 10 best paths */
+  mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10);
+  assert( nLoop<=pWInfo->pTabList->nSrc );
+  WHERETRACE(0x002, ("---- begin solver.  (nRowEst=%d)\n", nRowEst));
+
+  /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this
+  ** case the purpose of this call is to estimate the number of rows returned
+  ** by the overall query. Once this estimate has been obtained, the caller
+  ** will invoke this function a second time, passing the estimate as the
+  ** nRowEst parameter.  */
+  if( pWInfo->pOrderBy==0 || nRowEst==0 ){
+    nOrderBy = 0;
+  }else{
+    nOrderBy = pWInfo->pOrderBy->nExpr;
+  }
+
+  /* Allocate and initialize space for aTo, aFrom and aSortCost[] */
+  nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
+  nSpace += sizeof(LogEst) * nOrderBy;
+  pSpace = sqlite3DbMallocRaw(db, nSpace);
+  if( pSpace==0 ) return SQLITE_NOMEM;
+  aTo = (WherePath*)pSpace;
+  aFrom = aTo+mxChoice;
+  memset(aFrom, 0, sizeof(aFrom[0]));
+  pX = (WhereLoop**)(aFrom+mxChoice);
+  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
+    pFrom->aLoop = pX;
+  }
+  if( nOrderBy ){
+    /* If there is an ORDER BY clause and it is not being ignored, set up
+    ** space for the aSortCost[] array. Each element of the aSortCost array
+    ** is either zero - meaning it has not yet been initialized - or the
+    ** cost of sorting nRowEst rows of data where the first X terms of
+    ** the ORDER BY clause are already in order, where X is the array 
+    ** index.  */
+    aSortCost = (LogEst*)pX;
+    memset(aSortCost, 0, sizeof(LogEst) * nOrderBy);
+  }
+  assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] );
+  assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX );
+
+  /* Seed the search with a single WherePath containing zero WhereLoops.
+  **
+  ** TUNING: Do not let the number of iterations go above 28.  If the cost
+  ** of computing an automatic index is not paid back within the first 28
+  ** rows, then do not use the automatic index. */
+  aFrom[0].nRow = MIN(pParse->nQueryLoop, 48);  assert( 48==sqlite3LogEst(28) );
+  nFrom = 1;
+  assert( aFrom[0].isOrdered==0 );
+  if( nOrderBy ){
+    /* If nLoop is zero, then there are no FROM terms in the query. Since
+    ** in this case the query may return a maximum of one row, the results
+    ** are already in the requested order. Set isOrdered to nOrderBy to
+    ** indicate this. Or, if nLoop is greater than zero, set isOrdered to
+    ** -1, indicating that the result set may or may not be ordered, 
+    ** depending on the loops added to the current plan.  */
+    aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy;
+  }
+
+  /* Compute successively longer WherePaths using the previous generation
+  ** of WherePaths as the basis for the next.  Keep track of the mxChoice
+  ** best paths at each generation */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    nTo = 0;
+    for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){
+      for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
+        LogEst nOut;                      /* Rows visited by (pFrom+pWLoop) */
+        LogEst rCost;                     /* Cost of path (pFrom+pWLoop) */
+        LogEst rUnsorted;                 /* Unsorted cost of (pFrom+pWLoop) */
+        i8 isOrdered = pFrom->isOrdered;  /* isOrdered for (pFrom+pWLoop) */
+        Bitmask maskNew;                  /* Mask of src visited by (..) */
+        Bitmask revMask = 0;              /* Mask of rev-order loops for (..) */
+
+        if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
+        /* At this point, pWLoop is a candidate to be the next loop. 
+        ** Compute its cost */
+        rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
+        rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted);
+        nOut = pFrom->nRow + pWLoop->nOut;
+        maskNew = pFrom->maskLoop | pWLoop->maskSelf;
+        if( isOrdered<0 ){
+          isOrdered = wherePathSatisfiesOrderBy(pWInfo,
+                       pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
+                       iLoop, pWLoop, &revMask);
+        }else{
+          revMask = pFrom->revLoop;
+        }
+        if( isOrdered>=0 && isOrdered<nOrderBy ){
+          if( aSortCost[isOrdered]==0 ){
+            aSortCost[isOrdered] = whereSortingCost(
+                pWInfo, nRowEst, nOrderBy, isOrdered
+            );
+          }
+          rCost = sqlite3LogEstAdd(rUnsorted, aSortCost[isOrdered]);
+
+          WHERETRACE(0x002,
+              ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n",
+               aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, 
+               rUnsorted, rCost));
+        }else{
+          rCost = rUnsorted;
+        }
+
+        /* Check to see if pWLoop should be added to the set of
+        ** mxChoice best-so-far paths.
+        **
+        ** First look for an existing path among best-so-far paths
+        ** that covers the same set of loops and has the same isOrdered
+        ** setting as the current path candidate.
+        **
+        ** The term "((pTo->isOrdered^isOrdered)&0x80)==0" is equivalent
+        ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range
+        ** of legal values for isOrdered, -1..64.
+        */
+        for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){
+          if( pTo->maskLoop==maskNew
+           && ((pTo->isOrdered^isOrdered)&0x80)==0
+          ){
+            testcase( jj==nTo-1 );
+            break;
+          }
+        }
+        if( jj>=nTo ){
+          /* None of the existing best-so-far paths match the candidate. */
+          if( nTo>=mxChoice
+           && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted))
+          ){
+            /* The current candidate is no better than any of the mxChoice
+            ** paths currently in the best-so-far buffer.  So discard
+            ** this candidate as not viable. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+            }
+#endif
+            continue;
+          }
+          /* If we reach this points it means that the new candidate path
+          ** needs to be added to the set of best-so-far paths. */
+          if( nTo<mxChoice ){
+            /* Increase the size of the aTo set by one */
+            jj = nTo++;
+          }else{
+            /* New path replaces the prior worst to keep count below mxChoice */
+            jj = mxI;
+          }
+          pTo = &aTo[jj];
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                isOrdered>=0 ? isOrdered+'0' : '?');
+          }
+#endif
+        }else{
+          /* Control reaches here if best-so-far path pTo=aTo[jj] covers the
+          ** same set of loops and has the sam isOrdered setting as the
+          ** candidate path.  Check to see if the candidate should replace
+          ** pTo or if the candidate should be skipped */
+          if( pTo->rCost<rCost || (pTo->rCost==rCost && pTo->nRow<=nOut) ){
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf(
+                  "Skip   %s cost=%-3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                  isOrdered>=0 ? isOrdered+'0' : '?');
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
+                  wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                  pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+            }
+#endif
+            /* Discard the candidate path from further consideration */
+            testcase( pTo->rCost==rCost );
+            continue;
+          }
+          testcase( pTo->rCost==rCost+1 );
+          /* Control reaches here if the candidate path is better than the
+          ** pTo path.  Replace pTo with the candidate. */
+#ifdef WHERETRACE_ENABLED /* 0x4 */
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf(
+                "Update %s cost=%-3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
+                isOrdered>=0 ? isOrdered+'0' : '?');
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+                pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?');
+          }
+#endif
+        }
+        /* pWLoop is a winner.  Add it to the set of best so far */
+        pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
+        pTo->revLoop = revMask;
+        pTo->nRow = nOut;
+        pTo->rCost = rCost;
+        pTo->rUnsorted = rUnsorted;
+        pTo->isOrdered = isOrdered;
+        memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
+        pTo->aLoop[iLoop] = pWLoop;
+        if( nTo>=mxChoice ){
+          mxI = 0;
+          mxCost = aTo[0].rCost;
+          mxUnsorted = aTo[0].nRow;
+          for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){
+            if( pTo->rCost>mxCost 
+             || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) 
+            ){
+              mxCost = pTo->rCost;
+              mxUnsorted = pTo->rUnsorted;
+              mxI = jj;
+            }
+          }
+        }
+      }
+    }
+
+#ifdef WHERETRACE_ENABLED  /* >=2 */
+    if( sqlite3WhereTrace & 0x02 ){
+      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
+      for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
+        sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
+           wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+           pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?');
+        if( pTo->isOrdered>0 ){
+          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
+        }else{
+          sqlite3DebugPrintf("\n");
+        }
+      }
+    }
+#endif
+
+    /* Swap the roles of aFrom and aTo for the next generation */
+    pFrom = aTo;
+    aTo = aFrom;
+    aFrom = pFrom;
+    nFrom = nTo;
+  }
+
+  if( nFrom==0 ){
+    sqlite3ErrorMsg(pParse, "no query solution");
+    sqlite3DbFree(db, pSpace);
+    return SQLITE_ERROR;
+  }
+  
+  /* Find the lowest cost path.  pFrom will be left pointing to that path */
+  pFrom = aFrom;
+  for(ii=1; ii<nFrom; ii++){
+    if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
+  }
+  assert( pWInfo->nLevel==nLoop );
+  /* Load the lowest cost path into pWInfo */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    WhereLevel *pLevel = pWInfo->a + iLoop;
+    pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
+    pLevel->iFrom = pWLoop->iTab;
+    pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
+  }
+  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
+   && nRowEst
+  ){
+    Bitmask notUsed;
+    int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,
+                 WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], &notUsed);
+    if( rc==pWInfo->pResultSet->nExpr ){
+      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+    }
+  }
+  if( pWInfo->pOrderBy ){
+    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
+      if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){
+        pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+      }
+    }else{
+      pWInfo->nOBSat = pFrom->isOrdered;
+      if( pWInfo->nOBSat<0 ) pWInfo->nOBSat = 0;
+      pWInfo->revMask = pFrom->revLoop;
+    }
+    if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
+        && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
+    ){
+      Bitmask revMask = 0;
+      int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, 
+          pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], &revMask
+      );
+      assert( pWInfo->sorted==0 );
+      if( nOrder==pWInfo->pOrderBy->nExpr ){
+        pWInfo->sorted = 1;
+        pWInfo->revMask = revMask;
+      }
+    }
+  }
+
+
+  pWInfo->nRowOut = pFrom->nRow;
+
+  /* Free temporary memory and return success */
+  sqlite3DbFree(db, pSpace);
+  return SQLITE_OK;
+}
+
+/*
+** Most queries use only a single table (they are not joins) and have
+** simple == constraints against indexed fields.  This routine attempts
+** to plan those simple cases using much less ceremony than the
+** general-purpose query planner, and thereby yield faster sqlite3_prepare()
+** times for the common case.
+**
+** Return non-zero on success, if this query can be handled by this
+** no-frills query planner.  Return zero if this query needs the 
+** general-purpose query planner.
+*/
+static int whereShortCut(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo;
+  struct SrcList_item *pItem;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  WhereLoop *pLoop;
+  int iCur;
+  int j;
+  Table *pTab;
+  Index *pIdx;
+  
+  pWInfo = pBuilder->pWInfo;
+  if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0;
+  assert( pWInfo->pTabList->nSrc>=1 );
+  pItem = pWInfo->pTabList->a;
+  pTab = pItem->pTab;
+  if( IsVirtual(pTab) ) return 0;
+  if( pItem->fg.isIndexedBy ) return 0;
+  iCur = pItem->iCursor;
+  pWC = &pWInfo->sWC;
+  pLoop = pBuilder->pNew;
+  pLoop->wsFlags = 0;
+  pLoop->nSkip = 0;
+  pTerm = sqlite3WhereFindTerm(pWC, iCur, -1, 0, WO_EQ|WO_IS, 0);
+  if( pTerm ){
+    testcase( pTerm->eOperator & WO_IS );
+    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
+    pLoop->aLTerm[0] = pTerm;
+    pLoop->nLTerm = 1;
+    pLoop->u.btree.nEq = 1;
+    /* TUNING: Cost of a rowid lookup is 10 */
+    pLoop->rRun = 33;  /* 33==sqlite3LogEst(10) */
+  }else{
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      int opMask;
+      assert( pLoop->aLTermSpace==pLoop->aLTerm );
+      if( !IsUniqueIndex(pIdx)
+       || pIdx->pPartIdxWhere!=0 
+       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
+      ) continue;
+      opMask = pIdx->uniqNotNull ? (WO_EQ|WO_IS) : WO_EQ;
+      for(j=0; j<pIdx->nKeyCol; j++){
+        pTerm = sqlite3WhereFindTerm(pWC, iCur, j, 0, opMask, pIdx);
+        if( pTerm==0 ) break;
+        testcase( pTerm->eOperator & WO_IS );
+        pLoop->aLTerm[j] = pTerm;
+      }
+      if( j!=pIdx->nKeyCol ) continue;
+      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
+      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
+        pLoop->wsFlags |= WHERE_IDX_ONLY;
+      }
+      pLoop->nLTerm = j;
+      pLoop->u.btree.nEq = j;
+      pLoop->u.btree.pIndex = pIdx;
+      /* TUNING: Cost of a unique index lookup is 15 */
+      pLoop->rRun = 39;  /* 39==sqlite3LogEst(15) */
+      break;
+    }
+  }
+  if( pLoop->wsFlags ){
+    pLoop->nOut = (LogEst)1;
+    pWInfo->a[0].pWLoop = pLoop;
+    pLoop->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
+    pWInfo->a[0].iTabCur = iCur;
+    pWInfo->nRowOut = 1;
+    if( pWInfo->pOrderBy ) pWInfo->nOBSat =  pWInfo->pOrderBy->nExpr;
+    if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+#ifdef SQLITE_DEBUG
+    pLoop->cId = '0';
+#endif
+    return 1;
+  }
+  return 0;
+}
+
+/*
+** Generate the beginning of the loop used for WHERE clause processing.
+** The return value is a pointer to an opaque structure that contains
+** information needed to terminate the loop.  Later, the calling routine
+** should invoke sqlite3WhereEnd() with the return value of this function
+** in order to complete the WHERE clause processing.
+**
+** If an error occurs, this routine returns NULL.
+**
+** The basic idea is to do a nested loop, one loop for each table in
+** the FROM clause of a select.  (INSERT and UPDATE statements are the
+** same as a SELECT with only a single table in the FROM clause.)  For
+** example, if the SQL is this:
+**
+**       SELECT * FROM t1, t2, t3 WHERE ...;
+**
+** Then the code generated is conceptually like the following:
+**
+**      foreach row1 in t1 do       \    Code generated
+**        foreach row2 in t2 do      |-- by sqlite3WhereBegin()
+**          foreach row3 in t3 do   /
+**            ...
+**          end                     \    Code generated
+**        end                        |-- by sqlite3WhereEnd()
+**      end                         /
+**
+** Note that the loops might not be nested in the order in which they
+** appear in the FROM clause if a different order is better able to make
+** use of indices.  Note also that when the IN operator appears in
+** the WHERE clause, it might result in additional nested loops for
+** scanning through all values on the right-hand side of the IN.
+**
+** There are Btree cursors associated with each table.  t1 uses cursor
+** number pTabList->a[0].iCursor.  t2 uses the cursor pTabList->a[1].iCursor.
+** And so forth.  This routine generates code to open those VDBE cursors
+** and sqlite3WhereEnd() generates the code to close them.
+**
+** The code that sqlite3WhereBegin() generates leaves the cursors named
+** in pTabList pointing at their appropriate entries.  The [...] code
+** can use OP_Column and OP_Rowid opcodes on these cursors to extract
+** data from the various tables of the loop.
+**
+** If the WHERE clause is empty, the foreach loops must each scan their
+** entire tables.  Thus a three-way join is an O(N^3) operation.  But if
+** the tables have indices and there are terms in the WHERE clause that
+** refer to those indices, a complete table scan can be avoided and the
+** code will run much faster.  Most of the work of this routine is checking
+** to see if there are indices that can be used to speed up the loop.
+**
+** Terms of the WHERE clause are also used to limit which rows actually
+** make it to the "..." in the middle of the loop.  After each "foreach",
+** terms of the WHERE clause that use only terms in that loop and outer
+** loops are evaluated and if false a jump is made around all subsequent
+** inner loops (or around the "..." if the test occurs within the inner-
+** most loop)
+**
+** OUTER JOINS
+**
+** An outer join of tables t1 and t2 is conceptally coded as follows:
+**
+**    foreach row1 in t1 do
+**      flag = 0
+**      foreach row2 in t2 do
+**        start:
+**          ...
+**          flag = 1
+**      end
+**      if flag==0 then
+**        move the row2 cursor to a null row
+**        goto start
+**      fi
+**    end
+**
+** ORDER BY CLAUSE PROCESSING
+**
+** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
+** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
+** if there is one.  If there is no ORDER BY clause or if this routine
+** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
+**
+** The iIdxCur parameter is the cursor number of an index.  If 
+** WHERE_ONETABLE_ONLY is set, iIdxCur is the cursor number of an index
+** to use for OR clause processing.  The WHERE clause should use this
+** specific cursor.  If WHERE_ONEPASS_DESIRED is set, then iIdxCur is
+** the first cursor in an array of cursors for all indices.  iIdxCur should
+** be used to compute the appropriate cursor depending on which index is
+** used.
+*/
+SQLITE_PRIVATE WhereInfo *sqlite3WhereBegin(
+  Parse *pParse,        /* The parser context */
+  SrcList *pTabList,    /* FROM clause: A list of all tables to be scanned */
+  Expr *pWhere,         /* The WHERE clause */
+  ExprList *pOrderBy,   /* An ORDER BY (or GROUP BY) clause, or NULL */
+  ExprList *pResultSet, /* Result set of the query */
+  u16 wctrlFlags,       /* One of the WHERE_* flags defined in sqliteInt.h */
+  int iIdxCur           /* If WHERE_ONETABLE_ONLY is set, index cursor number */
+){
+  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
+  int nTabList;              /* Number of elements in pTabList */
+  WhereInfo *pWInfo;         /* Will become the return value of this function */
+  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
+  Bitmask notReady;          /* Cursors that are not yet positioned */
+  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
+  WhereMaskSet *pMaskSet;    /* The expression mask set */
+  WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
+  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
+  int ii;                    /* Loop counter */
+  sqlite3 *db;               /* Database connection */
+  int rc;                    /* Return code */
+  u8 bFordelete = 0;
+
+  assert( (wctrlFlags & WHERE_ONEPASS_MULTIROW)==0 || (
+        (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
+     && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 
+  ));
+
+  /* Variable initialization */
+  db = pParse->db;
+  memset(&sWLB, 0, sizeof(sWLB));
+
+  /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */
+  testcase( pOrderBy && pOrderBy->nExpr==BMS-1 );
+  if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0;
+  sWLB.pOrderBy = pOrderBy;
+
+  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+    wctrlFlags &= ~WHERE_WANT_DISTINCT;
+  }
+
+  /* The number of tables in the FROM clause is limited by the number of
+  ** bits in a Bitmask 
+  */
+  testcase( pTabList->nSrc==BMS );
+  if( pTabList->nSrc>BMS ){
+    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
+    return 0;
+  }
+
+  /* This function normally generates a nested loop for all tables in 
+  ** pTabList.  But if the WHERE_ONETABLE_ONLY flag is set, then we should
+  ** only generate code for the first table in pTabList and assume that
+  ** any cursors associated with subsequent tables are uninitialized.
+  */
+  nTabList = (wctrlFlags & WHERE_ONETABLE_ONLY) ? 1 : pTabList->nSrc;
+
+  /* Allocate and initialize the WhereInfo structure that will become the
+  ** return value. A single allocation is used to store the WhereInfo
+  ** struct, the contents of WhereInfo.a[], the WhereClause structure
+  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
+  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
+  ** some architectures. Hence the ROUND8() below.
+  */
+  nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
+  pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
+  if( db->mallocFailed ){
+    sqlite3DbFree(db, pWInfo);
+    pWInfo = 0;
+    goto whereBeginError;
+  }
+  pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1;
+  pWInfo->nLevel = nTabList;
+  pWInfo->pParse = pParse;
+  pWInfo->pTabList = pTabList;
+  pWInfo->pOrderBy = pOrderBy;
+  pWInfo->pResultSet = pResultSet;
+  pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v);
+  pWInfo->wctrlFlags = wctrlFlags;
+  pWInfo->savedNQueryLoop = pParse->nQueryLoop;
+  assert( pWInfo->eOnePass==ONEPASS_OFF );  /* ONEPASS defaults to OFF */
+  pMaskSet = &pWInfo->sMaskSet;
+  sWLB.pWInfo = pWInfo;
+  sWLB.pWC = &pWInfo->sWC;
+  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
+  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
+  whereLoopInit(sWLB.pNew);
+#ifdef SQLITE_DEBUG
+  sWLB.pNew->cId = '*';
+#endif
+
+  /* Split the WHERE clause into separate subexpressions where each
+  ** subexpression is separated by an AND operator.
+  */
+  initMaskSet(pMaskSet);
+  sqlite3WhereClauseInit(&pWInfo->sWC, pWInfo);
+  sqlite3WhereSplit(&pWInfo->sWC, pWhere, TK_AND);
+    
+  /* Special case: a WHERE clause that is constant.  Evaluate the
+  ** expression and either jump over all of the code or fall thru.
+  */
+  for(ii=0; ii<sWLB.pWC->nTerm; ii++){
+    if( nTabList==0 || sqlite3ExprIsConstantNotJoin(sWLB.pWC->a[ii].pExpr) ){
+      sqlite3ExprIfFalse(pParse, sWLB.pWC->a[ii].pExpr, pWInfo->iBreak,
+                         SQLITE_JUMPIFNULL);
+      sWLB.pWC->a[ii].wtFlags |= TERM_CODED;
+    }
+  }
+
+  /* Special case: No FROM clause
+  */
+  if( nTabList==0 ){
+    if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
+    if( wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+  }
+
+  /* Assign a bit from the bitmask to every term in the FROM clause.
+  **
+  ** The N-th term of the FROM clause is assigned a bitmask of 1<<N.
+  **
+  ** The rule of the previous sentence ensures thta if X is the bitmask for
+  ** a table T, then X-1 is the bitmask for all other tables to the left of T.
+  ** Knowing the bitmask for all tables to the left of a left join is
+  ** important.  Ticket #3015.
+  **
+  ** Note that bitmasks are created for all pTabList->nSrc tables in
+  ** pTabList, not just the first nTabList tables.  nTabList is normally
+  ** equal to pTabList->nSrc but might be shortened to 1 if the
+  ** WHERE_ONETABLE_ONLY flag is set.
+  */
+  for(ii=0; ii<pTabList->nSrc; ii++){
+    createMask(pMaskSet, pTabList->a[ii].iCursor);
+    sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
+  }
+#ifdef SQLITE_DEBUG
+  for(ii=0; ii<pTabList->nSrc; ii++){
+    Bitmask m = sqlite3WhereGetMask(pMaskSet, pTabList->a[ii].iCursor);
+    assert( m==MASKBIT(ii) );
+  }
+#endif
+
+  /* Analyze all of the subexpressions. */
+  sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
+  if( db->mallocFailed ) goto whereBeginError;
+
+  if( wctrlFlags & WHERE_WANT_DISTINCT ){
+    if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
+      /* The DISTINCT marking is pointless.  Ignore it. */
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }else if( pOrderBy==0 ){
+      /* Try to ORDER BY the result set to make distinct processing easier */
+      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
+      pWInfo->pOrderBy = pResultSet;
+    }
+  }
+
+  /* Construct the WhereLoop objects */
+  WHERETRACE(0xffff,("*** Optimizer Start *** (wctrlFlags: 0x%x)\n",
+             wctrlFlags));
+#if defined(WHERETRACE_ENABLED)
+  if( sqlite3WhereTrace & 0x100 ){ /* Display all terms of the WHERE clause */
+    int i;
+    for(i=0; i<sWLB.pWC->nTerm; i++){
+      whereTermPrint(&sWLB.pWC->a[i], i);
+    }
+  }
+#endif
+
+  if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
+    rc = whereLoopAddAll(&sWLB);
+    if( rc ) goto whereBeginError;
+  
+#ifdef WHERETRACE_ENABLED
+    if( sqlite3WhereTrace ){    /* Display all of the WhereLoop objects */
+      WhereLoop *p;
+      int i;
+      static const char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
+                                             "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+        p->cId = zLabel[i%sizeof(zLabel)];
+        whereLoopPrint(p, sWLB.pWC);
+      }
+    }
+#endif
+  
+    wherePathSolver(pWInfo, 0);
+    if( db->mallocFailed ) goto whereBeginError;
+    if( pWInfo->pOrderBy ){
+       wherePathSolver(pWInfo, pWInfo->nRowOut+1);
+       if( db->mallocFailed ) goto whereBeginError;
+    }
+  }
+  if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
+     pWInfo->revMask = (Bitmask)(-1);
+  }
+  if( pParse->nErr || NEVER(db->mallocFailed) ){
+    goto whereBeginError;
+  }
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace ){
+    sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
+    if( pWInfo->nOBSat>0 ){
+      sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);
+    }
+    switch( pWInfo->eDistinct ){
+      case WHERE_DISTINCT_UNIQUE: {
+        sqlite3DebugPrintf("  DISTINCT=unique");
+        break;
+      }
+      case WHERE_DISTINCT_ORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=ordered");
+        break;
+      }
+      case WHERE_DISTINCT_UNORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=unordered");
+        break;
+      }
+    }
+    sqlite3DebugPrintf("\n");
+    for(ii=0; ii<pWInfo->nLevel; ii++){
+      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
+    }
+  }
+#endif
+  /* Attempt to omit tables from the join that do not effect the result */
+  if( pWInfo->nLevel>=2
+   && pResultSet!=0
+   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
+  ){
+    Bitmask tabUsed = sqlite3WhereExprListUsage(pMaskSet, pResultSet);
+    if( sWLB.pOrderBy ){
+      tabUsed |= sqlite3WhereExprListUsage(pMaskSet, sWLB.pOrderBy);
+    }
+    while( pWInfo->nLevel>=2 ){
+      WhereTerm *pTerm, *pEnd;
+      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+      if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break;
+      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
+       && (pLoop->wsFlags & WHERE_ONEROW)==0
+      ){
+        break;
+      }
+      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
+      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
+      for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){
+        if( (pTerm->prereqAll & pLoop->maskSelf)!=0
+         && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+        ){
+          break;
+        }
+      }
+      if( pTerm<pEnd ) break;
+      WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
+      pWInfo->nLevel--;
+      nTabList--;
+    }
+  }
+  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
+  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
+
+  /* If the caller is an UPDATE or DELETE statement that is requesting
+  ** to use a one-pass algorithm, determine if this is appropriate.
+  ** The one-pass algorithm only works if the WHERE clause constrains
+  ** the statement to update or delete a single row.
+  */
+  assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
+  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 ){
+    int wsFlags = pWInfo->a[0].pWLoop->wsFlags;
+    int bOnerow = (wsFlags & WHERE_ONEROW)!=0;
+    if( bOnerow || ( (wctrlFlags & WHERE_ONEPASS_MULTIROW)
+       && 0==(wsFlags & WHERE_VIRTUALTABLE)
+    )){
+      pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI;
+      if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){
+        if( wctrlFlags & WHERE_ONEPASS_MULTIROW ){
+          bFordelete = OPFLAG_FORDELETE;
+        }
+        pWInfo->a[0].pWLoop->wsFlags = (wsFlags & ~WHERE_IDX_ONLY);
+      }
+    }
+  }
+
+  /* Open all tables in the pTabList and any indices selected for
+  ** searching those tables.
+  */
+  for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
+    Table *pTab;     /* Table to open */
+    int iDb;         /* Index of database containing table/index */
+    struct SrcList_item *pTabItem;
+
+    pTabItem = &pTabList->a[pLevel->iFrom];
+    pTab = pTabItem->pTab;
+    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    pLoop = pLevel->pWLoop;
+    if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
+      /* Do nothing */
+    }else
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+      const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
+      int iCur = pTabItem->iCursor;
+      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
+    }else if( IsVirtual(pTab) ){
+      /* noop */
+    }else
+#endif
+    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+         && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
+      int op = OP_OpenRead;
+      if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[0] = pTabItem->iCursor;
+      };
+      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
+      assert( pTabItem->iCursor==pLevel->iTabCur );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS-1 );
+      testcase( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol==BMS );
+      if( pWInfo->eOnePass==ONEPASS_OFF && pTab->nCol<BMS && HasRowid(pTab) ){
+        Bitmask b = pTabItem->colUsed;
+        int n = 0;
+        for(; b; b=b>>1, n++){}
+        sqlite3VdbeChangeP4(v, sqlite3VdbeCurrentAddr(v)-1, 
+                            SQLITE_INT_TO_PTR(n), P4_INT32);
+        assert( n<=pTab->nCol );
+      }
+#ifdef SQLITE_ENABLE_CURSOR_HINTS
+      if( pLoop->u.btree.pIndex!=0 ){
+        sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ|bFordelete);
+      }else
+#endif
+      {
+        sqlite3VdbeChangeP5(v, bFordelete);
+      }
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+      sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,
+                            (const u8*)&pTabItem->colUsed, P4_INT64);
+#endif
+    }else{
+      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
+    }
+    if( pLoop->wsFlags & WHERE_INDEXED ){
+      Index *pIx = pLoop->u.btree.pIndex;
+      int iIndexCur;
+      int op = OP_OpenRead;
+      /* iIdxCur is always set if to a positive value if ONEPASS is possible */
+      assert( iIdxCur!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 );
+      if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx)
+       && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0
+      ){
+        /* This is one term of an OR-optimization using the PRIMARY KEY of a
+        ** WITHOUT ROWID table.  No need for a separate index */
+        iIndexCur = pLevel->iTabCur;
+        op = 0;
+      }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
+        Index *pJ = pTabItem->pTab->pIndex;
+        iIndexCur = iIdxCur;
+        assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
+        while( ALWAYS(pJ) && pJ!=pIx ){
+          iIndexCur++;
+          pJ = pJ->pNext;
+        }
+        op = OP_OpenWrite;
+        pWInfo->aiCurOnePass[1] = iIndexCur;
+      }else if( iIdxCur && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0 ){
+        iIndexCur = iIdxCur;
+        if( wctrlFlags & WHERE_REOPEN_IDX ) op = OP_ReopenIdx;
+      }else{
+        iIndexCur = pParse->nTab++;
+      }
+      pLevel->iIdxCur = iIndexCur;
+      assert( pIx->pSchema==pTab->pSchema );
+      assert( iIndexCur>=0 );
+      if( op ){
+        sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb);
+        sqlite3VdbeSetP4KeyInfo(pParse, pIx);
+        if( (pLoop->wsFlags & WHERE_CONSTRAINT)!=0
+         && (pLoop->wsFlags & (WHERE_COLUMN_RANGE|WHERE_SKIPSCAN))==0
+         && (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0
+        ){
+          sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Hint to COMDB2 */
+        }
+        VdbeComment((v, "%s", pIx->zName));
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+        {
+          u64 colUsed = 0;
+          int ii, jj;
+          for(ii=0; ii<pIx->nColumn; ii++){
+            jj = pIx->aiColumn[ii];
+            if( jj<0 ) continue;
+            if( jj>63 ) jj = 63;
+            if( (pTabItem->colUsed & MASKBIT(jj))==0 ) continue;
+            colUsed |= ((u64)1)<<(ii<63 ? ii : 63);
+          }
+          sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, iIndexCur, 0, 0,
+                                (u8*)&colUsed, P4_INT64);
+        }
+#endif /* SQLITE_ENABLE_COLUMN_USED_MASK */
+      }
+    }
+    if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);
+  }
+  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
+  if( db->mallocFailed ) goto whereBeginError;
+
+  /* Generate the code to do the search.  Each iteration of the for
+  ** loop below generates code for a single nested loop of the VM
+  ** program.
+  */
+  notReady = ~(Bitmask)0;
+  for(ii=0; ii<nTabList; ii++){
+    int addrExplain;
+    int wsFlags;
+    pLevel = &pWInfo->a[ii];
+    wsFlags = pLevel->pWLoop->wsFlags;
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+      constructAutomaticIndex(pParse, &pWInfo->sWC,
+                &pTabList->a[pLevel->iFrom], notReady, pLevel);
+      if( db->mallocFailed ) goto whereBeginError;
+    }
+#endif
+    addrExplain = sqlite3WhereExplainOneScan(
+        pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
+    );
+    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
+    notReady = sqlite3WhereCodeOneLoopStart(pWInfo, ii, notReady);
+    pWInfo->iContinue = pLevel->addrCont;
+    if( (wsFlags&WHERE_MULTI_OR)==0 && (wctrlFlags&WHERE_ONETABLE_ONLY)==0 ){
+      sqlite3WhereAddScanStatus(v, pTabList, pLevel, addrExplain);
+    }
+  }
+
+  /* Done. */
+  VdbeModuleComment((v, "Begin WHERE-core"));
+  return pWInfo;
+
+  /* Jump here if malloc fails */
+whereBeginError:
+  if( pWInfo ){
+    pParse->nQueryLoop = pWInfo->savedNQueryLoop;
+    whereInfoFree(db, pWInfo);
+  }
+  return 0;
+}
+
+/*
+** Generate the end of the WHERE loop.  See comments on 
+** sqlite3WhereBegin() for additional information.
+*/
+SQLITE_PRIVATE void sqlite3WhereEnd(WhereInfo *pWInfo){
+  Parse *pParse = pWInfo->pParse;
+  Vdbe *v = pParse->pVdbe;
+  int i;
+  WhereLevel *pLevel;
+  WhereLoop *pLoop;
+  SrcList *pTabList = pWInfo->pTabList;
+  sqlite3 *db = pParse->db;
+
+  /* Generate loop termination code.
+  */
+  VdbeModuleComment((v, "End WHERE-core"));
+  sqlite3ExprCacheClear(pParse);
+  for(i=pWInfo->nLevel-1; i>=0; i--){
+    int addr;
+    pLevel = &pWInfo->a[i];
+    pLoop = pLevel->pWLoop;
+    sqlite3VdbeResolveLabel(v, pLevel->addrCont);
+    if( pLevel->op!=OP_Noop ){
+      sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3);
+      sqlite3VdbeChangeP5(v, pLevel->p5);
+      VdbeCoverage(v);
+      VdbeCoverageIf(v, pLevel->op==OP_Next);
+      VdbeCoverageIf(v, pLevel->op==OP_Prev);
+      VdbeCoverageIf(v, pLevel->op==OP_VNext);
+    }
+    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
+      struct InLoop *pIn;
+      int j;
+      sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
+      for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
+        sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
+        sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop);
+        VdbeCoverage(v);
+        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen);
+        VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
+        sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
+      }
+    }
+    sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
+    if( pLevel->addrSkip ){
+      sqlite3VdbeGoto(v, pLevel->addrSkip);
+      VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName));
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip);
+      sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
+    }
+#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
+    if( pLevel->addrLikeRep ){
+      int op;
+      if( sqlite3VdbeGetOp(v, pLevel->addrLikeRep-1)->p1 ){
+        op = OP_DecrJumpZero;
+      }else{
+        op = OP_JumpZeroIncr;
+      }
+      sqlite3VdbeAddOp2(v, op, pLevel->iLikeRepCntr, pLevel->addrLikeRep);
+      VdbeCoverage(v);
+    }
+#endif
+    if( pLevel->iLeftJoin ){
+      addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
+      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
+      if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
+      }
+      if( pLoop->wsFlags & WHERE_INDEXED ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
+      }
+      if( pLevel->op==OP_Return ){
+        sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
+      }else{
+        sqlite3VdbeGoto(v, pLevel->addrFirst);
+      }
+      sqlite3VdbeJumpHere(v, addr);
+    }
+    VdbeModuleComment((v, "End WHERE-loop%d: %s", i,
+                     pWInfo->pTabList->a[pLevel->iFrom].pTab->zName));
+  }
+
+  /* The "break" point is here, just past the end of the outer loop.
+  ** Set it.
+  */
+  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);
+
+  assert( pWInfo->nLevel<=pTabList->nSrc );
+  for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
+    int k, last;
+    VdbeOp *pOp;
+    Index *pIdx = 0;
+    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
+    Table *pTab = pTabItem->pTab;
+    assert( pTab!=0 );
+    pLoop = pLevel->pWLoop;
+
+    /* For a co-routine, change all OP_Column references to the table of
+    ** the co-routine into OP_Copy of result contained in a register.
+    ** OP_Rowid becomes OP_Null.
+    */
+    if( pTabItem->fg.viaCoroutine && !db->mallocFailed ){
+      translateColumnToCopy(v, pLevel->addrBody, pLevel->iTabCur,
+                            pTabItem->regResult, 0);
+      continue;
+    }
+
+    /* Close all of the cursors that were opened by sqlite3WhereBegin.
+    ** Except, do not close cursors that will be reused by the OR optimization
+    ** (WHERE_OMIT_OPEN_CLOSE).  And do not close the OP_OpenWrite cursors
+    ** created for the ONEPASS optimization.
+    */
+    if( (pTab->tabFlags & TF_Ephemeral)==0
+     && pTab->pSelect==0
+     && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
+    ){
+      int ws = pLoop->wsFlags;
+      if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
+        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
+      }
+      if( (ws & WHERE_INDEXED)!=0
+       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
+       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
+      ){
+        sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
+      }
+    }
+
+    /* If this scan uses an index, make VDBE code substitutions to read data
+    ** from the index instead of from the table where possible.  In some cases
+    ** this optimization prevents the table from ever being read, which can
+    ** yield a significant performance boost.
+    ** 
+    ** Calls to the code generator in between sqlite3WhereBegin and
+    ** sqlite3WhereEnd will have created code that references the table
+    ** directly.  This loop scans all that code looking for opcodes
+    ** that reference the table and converts them into opcodes that
+    ** reference the index.
+    */
+    if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
+      pIdx = pLoop->u.btree.pIndex;
+    }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
+      pIdx = pLevel->u.pCovidx;
+    }
+    if( pIdx
+     && (pWInfo->eOnePass==ONEPASS_OFF || !HasRowid(pIdx->pTable))
+     && !db->mallocFailed
+    ){
+      last = sqlite3VdbeCurrentAddr(v);
+      k = pLevel->addrBody;
+      pOp = sqlite3VdbeGetOp(v, k);
+      for(; k<last; k++, pOp++){
+        if( pOp->p1!=pLevel->iTabCur ) continue;
+        if( pOp->opcode==OP_Column ){
+          int x = pOp->p2;
+          assert( pIdx->pTable==pTab );
+          if( !HasRowid(pTab) ){
+            Index *pPk = sqlite3PrimaryKeyIndex(pTab);
+            x = pPk->aiColumn[x];
+            assert( x>=0 );
+          }
+          x = sqlite3ColumnOfIndex(pIdx, x);
+          if( x>=0 ){
+            pOp->p2 = x;
+            pOp->p1 = pLevel->iIdxCur;
+          }
+          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 );
+        }else if( pOp->opcode==OP_Rowid ){
+          pOp->p1 = pLevel->iIdxCur;
+          pOp->opcode = OP_IdxRowid;
+        }
+      }
+    }
+  }
+
+  /* Final cleanup
+  */
+  pParse->nQueryLoop = pWInfo->savedNQueryLoop;
+  whereInfoFree(db, pWInfo);
+  return;
+}
+
+/************** End of where.c ***********************************************/
+/************** Begin file parse.c *******************************************/
+/*
+** 2000-05-29
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Driver template for the LEMON parser generator.
+**
+** The "lemon" program processes an LALR(1) input grammar file, then uses
+** this template to construct a parser.  The "lemon" program inserts text
+** at each "%%" line.  Also, any "P-a-r-s-e" identifer prefix (without the
+** interstitial "-" characters) contained in this template is changed into
+** the value of the %name directive from the grammar.  Otherwise, the content
+** of this template is copied straight through into the generate parser
+** source file.
+**
+** The following is the concatenation of all %include directives from the
+** input grammar file:
+*/
+/* #include <stdio.h> */
+/************ Begin %include sections from the grammar ************************/
+
+/* #include "sqliteInt.h" */
+
+/*
+** Disable all error recovery processing in the parser push-down
+** automaton.
+*/
+#define YYNOERRORRECOVERY 1
+
+/*
+** Make yytestcase() the same as testcase()
+*/
+#define yytestcase(X) testcase(X)
+
+/*
+** Indicate that sqlite3ParserFree() will never be called with a null
+** pointer.
+*/
+#define YYPARSEFREENEVERNULL 1
+
+/*
+** Alternative datatype for the argument to the malloc() routine passed
+** into sqlite3ParserAlloc().  The default is size_t.
+*/
+#define YYMALLOCARGTYPE  u64
+
+/*
+** An instance of this structure holds information about the
+** LIMIT clause of a SELECT statement.
+*/
+struct LimitVal {
+  Expr *pLimit;    /* The LIMIT expression.  NULL if there is no limit */
+  Expr *pOffset;   /* The OFFSET expression.  NULL if there is none */
+};
+
+/*
+** An instance of this structure is used to store the LIKE,
+** GLOB, NOT LIKE, and NOT GLOB operators.
+*/
+struct LikeOp {
+  Token eOperator;  /* "like" or "glob" or "regexp" */
+  int bNot;         /* True if the NOT keyword is present */
+};
+
+/*
+** An instance of the following structure describes the event of a
+** TRIGGER.  "a" is the event type, one of TK_UPDATE, TK_INSERT,
+** TK_DELETE, or TK_INSTEAD.  If the event is of the form
+**
+**      UPDATE ON (a,b,c)
+**
+** Then the "b" IdList records the list "a,b,c".
+*/
+struct TrigEvent { int a; IdList * b; };
+
+/*
+** An instance of this structure holds the ATTACH key and the key type.
+*/
+struct AttachKey { int type;  Token key; };
+
+
+  /*
+  ** For a compound SELECT statement, make sure p->pPrior->pNext==p for
+  ** all elements in the list.  And make sure list length does not exceed
+  ** SQLITE_LIMIT_COMPOUND_SELECT.
+  */
+  static void parserDoubleLinkSelect(Parse *pParse, Select *p){
+    if( p->pPrior ){
+      Select *pNext = 0, *pLoop;
+      int mxSelect, cnt = 0;
+      for(pLoop=p; pLoop; pNext=pLoop, pLoop=pLoop->pPrior, cnt++){
+        pLoop->pNext = pNext;
+        pLoop->selFlags |= SF_Compound;
+      }
+      if( (p->selFlags & SF_MultiValue)==0 && 
+        (mxSelect = pParse->db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT])>0 &&
+        cnt>mxSelect
+      ){
+        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
+      }
+    }
+  }
+
+  /* This is a utility routine used to set the ExprSpan.zStart and
+  ** ExprSpan.zEnd values of pOut so that the span covers the complete
+  ** range of text beginning with pStart and going to the end of pEnd.
+  */
+  static void spanSet(ExprSpan *pOut, Token *pStart, Token *pEnd){
+    pOut->zStart = pStart->z;
+    pOut->zEnd = &pEnd->z[pEnd->n];
+  }
+
+  /* Construct a new Expr object from a single identifier.  Use the
+  ** new Expr to populate pOut.  Set the span of pOut to be the identifier
+  ** that created the expression.
+  */
+  static void spanExpr(ExprSpan *pOut, Parse *pParse, int op, Token *pValue){
+    pOut->pExpr = sqlite3PExpr(pParse, op, 0, 0, pValue);
+    pOut->zStart = pValue->z;
+    pOut->zEnd = &pValue->z[pValue->n];
+  }
+
+  /* This routine constructs a binary expression node out of two ExprSpan
+  ** objects and uses the result to populate a new ExprSpan object.
+  */
+  static void spanBinaryExpr(
+    ExprSpan *pOut,     /* Write the result here */
+    Parse *pParse,      /* The parsing context.  Errors accumulate here */
+    int op,             /* The binary operation */
+    ExprSpan *pLeft,    /* The left operand */
+    ExprSpan *pRight    /* The right operand */
+  ){
+    pOut->pExpr = sqlite3PExpr(pParse, op, pLeft->pExpr, pRight->pExpr, 0);
+    pOut->zStart = pLeft->zStart;
+    pOut->zEnd = pRight->zEnd;
+  }
+
+  /* If doNot is true, then add a TK_NOT Expr-node wrapper around the
+  ** outside of *ppExpr.
+  */
+  static void exprNot(Parse *pParse, int doNot, Expr **ppExpr){
+    if( doNot ) *ppExpr = sqlite3PExpr(pParse, TK_NOT, *ppExpr, 0, 0);
+  }
+
+  /* Construct an expression node for a unary postfix operator
+  */
+  static void spanUnaryPostfix(
+    ExprSpan *pOut,        /* Write the new expression node here */
+    Parse *pParse,         /* Parsing context to record errors */
+    int op,                /* The operator */
+    ExprSpan *pOperand,    /* The operand */
+    Token *pPostOp         /* The operand token for setting the span */
+  ){
+    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
+    pOut->zStart = pOperand->zStart;
+    pOut->zEnd = &pPostOp->z[pPostOp->n];
+  }                           
+
+  /* A routine to convert a binary TK_IS or TK_ISNOT expression into a
+  ** unary TK_ISNULL or TK_NOTNULL expression. */
+  static void binaryToUnaryIfNull(Parse *pParse, Expr *pY, Expr *pA, int op){
+    sqlite3 *db = pParse->db;
+    if( pY && pA && pY->op==TK_NULL ){
+      pA->op = (u8)op;
+      sqlite3ExprDelete(db, pA->pRight);
+      pA->pRight = 0;
+    }
+  }
+
+  /* Construct an expression node for a unary prefix operator
+  */
+  static void spanUnaryPrefix(
+    ExprSpan *pOut,        /* Write the new expression node here */
+    Parse *pParse,         /* Parsing context to record errors */
+    int op,                /* The operator */
+    ExprSpan *pOperand,    /* The operand */
+    Token *pPreOp         /* The operand token for setting the span */
+  ){
+    pOut->pExpr = sqlite3PExpr(pParse, op, pOperand->pExpr, 0, 0);
+    pOut->zStart = pPreOp->z;
+    pOut->zEnd = pOperand->zEnd;
+  }
+
+  /* Add a single new term to an ExprList that is used to store a
+  ** list of identifiers.  Report an error if the ID list contains
+  ** a COLLATE clause or an ASC or DESC keyword, except ignore the
+  ** error while parsing a legacy schema.
+  */
+  static ExprList *parserAddExprIdListTerm(
+    Parse *pParse,
+    ExprList *pPrior,
+    Token *pIdToken,
+    int hasCollate,
+    int sortOrder
+  ){
+    ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);
+    if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)
+        && pParse->db->init.busy==0
+    ){
+      sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",
+                         pIdToken->n, pIdToken->z);
+    }
+    sqlite3ExprListSetName(pParse, p, pIdToken, 1);
+    return p;
+  }
+/**************** End of %include directives **********************************/
+/* These constants specify the various numeric values for terminal symbols
+** in a format understandable to "makeheaders".  This section is blank unless
+** "lemon" is run with the "-m" command-line option.
+***************** Begin makeheaders token definitions *************************/
+/**************** End makeheaders token definitions ***************************/
+
+/* The next sections is a series of control #defines.
+** various aspects of the generated parser.
+**    YYCODETYPE         is the data type used to store the integer codes
+**                       that represent terminal and non-terminal symbols.
+**                       "unsigned char" is used if there are fewer than
+**                       256 symbols.  Larger types otherwise.
+**    YYNOCODE           is a number of type YYCODETYPE that is not used for
+**                       any terminal or nonterminal symbol.
+**    YYFALLBACK         If defined, this indicates that one or more tokens
+**                       (also known as: "terminal symbols") have fall-back
+**                       values which should be used if the original symbol
+**                       would not parse.  This permits keywords to sometimes
+**                       be used as identifiers, for example.
+**    YYACTIONTYPE       is the data type used for "action codes" - numbers
+**                       that indicate what to do in response to the next
+**                       token.
+**    sqlite3ParserTOKENTYPE     is the data type used for minor type for terminal
+**                       symbols.  Background: A "minor type" is a semantic
+**                       value associated with a terminal or non-terminal
+**                       symbols.  For example, for an "ID" terminal symbol,
+**                       the minor type might be the name of the identifier.
+**                       Each non-terminal can have a different minor type.
+**                       Terminal symbols all have the same minor type, though.
+**                       This macros defines the minor type for terminal 
+**                       symbols.
+**    YYMINORTYPE        is the data type used for all minor types.
+**                       This is typically a union of many types, one of
+**                       which is sqlite3ParserTOKENTYPE.  The entry in the union
+**                       for terminal symbols is called "yy0".
+**    YYSTACKDEPTH       is the maximum depth of the parser's stack.  If
+**                       zero the stack is dynamically sized using realloc()
+**    sqlite3ParserARG_SDECL     A static variable declaration for the %extra_argument
+**    sqlite3ParserARG_PDECL     A parameter declaration for the %extra_argument
+**    sqlite3ParserARG_STORE     Code to store %extra_argument into yypParser
+**    sqlite3ParserARG_FETCH     Code to extract %extra_argument from yypParser
+**    YYERRORSYMBOL      is the code number of the error symbol.  If not
+**                       defined, then do no error processing.
+**    YYNSTATE           the combined number of states.
+**    YYNRULE            the number of rules in the grammar
+**    YY_MAX_SHIFT       Maximum value for shift actions
+**    YY_MIN_SHIFTREDUCE Minimum value for shift-reduce actions
+**    YY_MAX_SHIFTREDUCE Maximum value for shift-reduce actions
+**    YY_MIN_REDUCE      Maximum value for reduce actions
+**    YY_ERROR_ACTION    The yy_action[] code for syntax error
+**    YY_ACCEPT_ACTION   The yy_action[] code for accept
+**    YY_NO_ACTION       The yy_action[] code for no-op
+*/
+#ifndef INTERFACE
+# define INTERFACE 1
+#endif
+/************* Begin control #defines *****************************************/
+#define YYCODETYPE unsigned char
+#define YYNOCODE 253
+#define YYACTIONTYPE unsigned short int
+#define YYWILDCARD 70
+#define sqlite3ParserTOKENTYPE Token
+typedef union {
+  int yyinit;
+  sqlite3ParserTOKENTYPE yy0;
+  int yy4;
+  struct TrigEvent yy90;
+  ExprSpan yy118;
+  TriggerStep* yy203;
+  struct {int value; int mask;} yy215;
+  SrcList* yy259;
+  struct LimitVal yy292;
+  Expr* yy314;
+  ExprList* yy322;
+  struct LikeOp yy342;
+  IdList* yy384;
+  Select* yy387;
+  With* yy451;
+} YYMINORTYPE;
+#ifndef YYSTACKDEPTH
+#define YYSTACKDEPTH 100
+#endif
+#define sqlite3ParserARG_SDECL Parse *pParse;
+#define sqlite3ParserARG_PDECL ,Parse *pParse
+#define sqlite3ParserARG_FETCH Parse *pParse = yypParser->pParse
+#define sqlite3ParserARG_STORE yypParser->pParse = pParse
+#define YYFALLBACK 1
+#define YYNSTATE             436
+#define YYNRULE              328
+#define YY_MAX_SHIFT         435
+#define YY_MIN_SHIFTREDUCE   649
+#define YY_MAX_SHIFTREDUCE   976
+#define YY_MIN_REDUCE        977
+#define YY_MAX_REDUCE        1304
+#define YY_ERROR_ACTION      1305
+#define YY_ACCEPT_ACTION     1306
+#define YY_NO_ACTION         1307
+/************* End control #defines *******************************************/
+
+/* The yyzerominor constant is used to initialize instances of
+** YYMINORTYPE objects to zero. */
+static const YYMINORTYPE yyzerominor = { 0 };
+
+/* Define the yytestcase() macro to be a no-op if is not already defined
+** otherwise.
+**
+** Applications can choose to define yytestcase() in the %include section
+** to a macro that can assist in verifying code coverage.  For production
+** code the yytestcase() macro should be turned off.  But it is useful
+** for testing.
+*/
+#ifndef yytestcase
+# define yytestcase(X)
+#endif
+
+
+/* Next are the tables used to determine what action to take based on the
+** current state and lookahead token.  These tables are used to implement
+** functions that take a state number and lookahead value and return an
+** action integer.  
+**
+** Suppose the action integer is N.  Then the action is determined as
+** follows
+**
+**   0 <= N <= YY_MAX_SHIFT             Shift N.  That is, push the lookahead
+**                                      token onto the stack and goto state N.
+**
+**   N between YY_MIN_SHIFTREDUCE       Shift to an arbitrary state then
+**     and YY_MAX_SHIFTREDUCE           reduce by rule N-YY_MIN_SHIFTREDUCE.
+**
+**   N between YY_MIN_REDUCE            Reduce by rule N-YY_MIN_REDUCE
+**     and YY_MAX_REDUCE
+
+**   N == YY_ERROR_ACTION               A syntax error has occurred.
+**
+**   N == YY_ACCEPT_ACTION              The parser accepts its input.
+**
+**   N == YY_NO_ACTION                  No such action.  Denotes unused
+**                                      slots in the yy_action[] table.
+**
+** The action table is constructed as a single large table named yy_action[].
+** Given state S and lookahead X, the action is computed as
+**
+**      yy_action[ yy_shift_ofst[S] + X ]
+**
+** If the index value yy_shift_ofst[S]+X is out of range or if the value
+** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X or if yy_shift_ofst[S]
+** is equal to YY_SHIFT_USE_DFLT, it means that the action is not in the table
+** and that yy_default[S] should be used instead.  
+**
+** The formula above is for computing the action when the lookahead is
+** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
+** a reduce action) then the yy_reduce_ofst[] array is used in place of
+** the yy_shift_ofst[] array and YY_REDUCE_USE_DFLT is used in place of
+** YY_SHIFT_USE_DFLT.
+**
+** The following are the tables generated in this section:
+**
+**  yy_action[]        A single table containing all actions.
+**  yy_lookahead[]     A table containing the lookahead for each entry in
+**                     yy_action.  Used to detect hash collisions.
+**  yy_shift_ofst[]    For each state, the offset into yy_action for
+**                     shifting terminals.
+**  yy_reduce_ofst[]   For each state, the offset into yy_action for
+**                     shifting non-terminals after a reduce.
+**  yy_default[]       Default action for each state.
+**
+*********** Begin parsing tables **********************************************/
+#define YY_ACTTAB_COUNT (1501)
+static const YYACTIONTYPE yy_action[] = {
+ /*     0 */   311, 1306,  145,  651,    2,  192,  652,  338,  780,   92,
+ /*    10 */    92,   92,   92,   85,   90,   90,   90,   90,   89,   89,
+ /*    20 */    88,   88,   88,   87,  335,   88,   88,   88,   87,  335,
+ /*    30 */   327,  856,  856,   92,   92,   92,   92,  697,   90,   90,
+ /*    40 */    90,   90,   89,   89,   88,   88,   88,   87,  335,   76,
+ /*    50 */   807,   74,   93,   94,   84,  868,  871,  860,  860,   91,
+ /*    60 */    91,   92,   92,   92,   92,  335,   90,   90,   90,   90,
+ /*    70 */    89,   89,   88,   88,   88,   87,  335,  311,  780,   90,
+ /*    80 */    90,   90,   90,   89,   89,   88,   88,   88,   87,  335,
+ /*    90 */   356,  808,  776,  701,  689,  689,   86,   83,  166,  257,
+ /*   100 */   809,  715,  430,   86,   83,  166,  324,  697,  856,  856,
+ /*   110 */   201,  158,  276,  387,  271,  386,  188,  689,  689,  828,
+ /*   120 */    86,   83,  166,  269,  833,   49,  123,   87,  335,   93,
+ /*   130 */    94,   84,  868,  871,  860,  860,   91,   91,   92,   92,
+ /*   140 */    92,   92,  239,   90,   90,   90,   90,   89,   89,   88,
+ /*   150 */    88,   88,   87,  335,  311,  763,  333,  332,  216,  408,
+ /*   160 */   394,   69,  231,  393,  690,  691,  396,  910,  251,  354,
+ /*   170 */   250,  288,  315,  430,  908,  430,  909,   89,   89,   88,
+ /*   180 */    88,   88,   87,  335,  391,  856,  856,  690,  691,  183,
+ /*   190 */    95,  123,  384,  381,  380,  833,   31,  833,   49,  912,
+ /*   200 */   912,  751,  752,  379,  123,  311,   93,   94,   84,  868,
+ /*   210 */   871,  860,  860,   91,   91,   92,   92,   92,   92,  114,
+ /*   220 */    90,   90,   90,   90,   89,   89,   88,   88,   88,   87,
+ /*   230 */   335,  430,  408,  399,  435,  657,  856,  856,  346,   57,
+ /*   240 */   232,  828,  109,  704,  366,  689,  689,  363,  825,  760,
+ /*   250 */    97,  749,  752,  833,   49,  708,  708,   93,   94,   84,
+ /*   260 */   868,  871,  860,  860,   91,   91,   92,   92,   92,   92,
+ /*   270 */   423,   90,   90,   90,   90,   89,   89,   88,   88,   88,
+ /*   280 */    87,  335,  311,  114,   22,  361,  688,   58,  408,  390,
+ /*   290 */   251,  349,  240,  213,  762,  689,  689,  847,  685,  115,
+ /*   300 */   361,  231,  393,  689,  689,  396,  183,  689,  689,  384,
+ /*   310 */   381,  380,  361,  856,  856,  690,  691,  160,  159,  223,
+ /*   320 */   379,  738,   25,  806,  707,  841,  143,  689,  689,  835,
+ /*   330 */   392,  339,  766,  766,   93,   94,   84,  868,  871,  860,
+ /*   340 */   860,   91,   91,   92,   92,   92,   92,  914,   90,   90,
+ /*   350 */    90,   90,   89,   89,   88,   88,   88,   87,  335,  311,
+ /*   360 */   840,  840,  840,  266,  257,  690,  691,  778,  706,   86,
+ /*   370 */    83,  166,  219,  690,  691,  737,    1,  690,  691,  689,
+ /*   380 */   689,  689,  689,  430,   86,   83,  166,  249,  688,  937,
+ /*   390 */   856,  856,  427,  699,  700,  828,  298,  690,  691,  221,
+ /*   400 */   686,  115,  123,  944,  795,  833,   48,  342,  305,  970,
+ /*   410 */   847,   93,   94,   84,  868,  871,  860,  860,   91,   91,
+ /*   420 */    92,   92,   92,   92,  114,   90,   90,   90,   90,   89,
+ /*   430 */    89,   88,   88,   88,   87,  335,  311,  940,  841,  679,
+ /*   440 */   713,  429,  835,  430,  251,  354,  250,  355,  288,  690,
+ /*   450 */   691,  690,  691,  285,  941,  340,  971,  287,  210,   23,
+ /*   460 */   174,  793,  832,  430,  353,  833,   10,  856,  856,   24,
+ /*   470 */   942,  151,  753,  840,  840,  840,  794,  968, 1290,  321,
+ /*   480 */   398, 1290,  356,  352,  754,  833,   49,  935,   93,   94,
+ /*   490 */    84,  868,  871,  860,  860,   91,   91,   92,   92,   92,
+ /*   500 */    92,  430,   90,   90,   90,   90,   89,   89,   88,   88,
+ /*   510 */    88,   87,  335,  311,  376,  114,  907,  705,  430,  907,
+ /*   520 */   328,  890,  114,  833,   10,  966,  430,  857,  857,  320,
+ /*   530 */   189,  163,  832,  165,  430,  906,  344,  323,  906,  904,
+ /*   540 */   833,   10,  965,  306,  856,  856,  187,  419,  833,   10,
+ /*   550 */   220,  869,  872,  832,  222,  403,  833,   49, 1219,  793,
+ /*   560 */    68,  937,  406,  245,   66,   93,   94,   84,  868,  871,
+ /*   570 */   860,  860,   91,   91,   92,   92,   92,   92,  861,   90,
+ /*   580 */    90,   90,   90,   89,   89,   88,   88,   88,   87,  335,
+ /*   590 */   311,  404,  213,  762,  834,  345,  114,  940,  902,  368,
+ /*   600 */   727,    5,  316,  192,  396,  772,  780,  269,  230,  242,
+ /*   610 */   771,  244,  397,  164,  941,  385,  123,  347,   55,  355,
+ /*   620 */   329,  856,  856,  728,  333,  332,  688,  968, 1291,  724,
+ /*   630 */   942, 1291,  413,  214,  833,    9,  362,  286,  955,  115,
+ /*   640 */   718,  311,   93,   94,   84,  868,  871,  860,  860,   91,
+ /*   650 */    91,   92,   92,   92,   92,  430,   90,   90,   90,   90,
+ /*   660 */    89,   89,   88,   88,   88,   87,  335,  912,  912, 1300,
+ /*   670 */  1300,  758,  856,  856,  325,  966,  780,  833,   35,  747,
+ /*   680 */   720,  334,  699,  700,  977,  652,  338,  243,  745,  920,
+ /*   690 */   920,  369,  187,   93,   94,   84,  868,  871,  860,  860,
+ /*   700 */    91,   91,   92,   92,   92,   92,  114,   90,   90,   90,
+ /*   710 */    90,   89,   89,   88,   88,   88,   87,  335,  311,  430,
+ /*   720 */   954,  430,  112,  310,  430,  693,  317,  698,  400,  430,
+ /*   730 */   793,  359,  430, 1017,  430,  192,  430,  401,  780,  430,
+ /*   740 */   360,  833,   36,  833,   12,  430,  833,   27,  316,  856,
+ /*   750 */   856,  833,   37,   20,  833,   38,  833,   39,  833,   28,
+ /*   760 */    72,  833,   29,  663,  664,  665,  264,  833,   40,  234,
+ /*   770 */    93,   94,   84,  868,  871,  860,  860,   91,   91,   92,
+ /*   780 */    92,   92,   92,  430,   90,   90,   90,   90,   89,   89,
+ /*   790 */    88,   88,   88,   87,  335,  311,  430,  698,  430,  917,
+ /*   800 */   147,  430,  165,  916,  275,  833,   41,  430,  780,  430,
+ /*   810 */    21,  430,  259,  430,  262,  274,  430,  367,  833,   42,
+ /*   820 */   833,   11,  430,  833,   43,  235,  856,  856,  793,  833,
+ /*   830 */    99,  833,   44,  833,   45,  833,   32,   75,  833,   46,
+ /*   840 */   305,  967,  257,  257,  833,   47,  311,   93,   94,   84,
+ /*   850 */   868,  871,  860,  860,   91,   91,   92,   92,   92,   92,
+ /*   860 */   430,   90,   90,   90,   90,   89,   89,   88,   88,   88,
+ /*   870 */    87,  335,  430,  186,  185,  184,  238,  856,  856,  650,
+ /*   880 */     2, 1064,  833,   33,  739,  217,  218,  257,  971,  257,
+ /*   890 */   426,  317,  257,  774,  833,  117,  257,  311,   93,   94,
+ /*   900 */    84,  868,  871,  860,  860,   91,   91,   92,   92,   92,
+ /*   910 */    92,  430,   90,   90,   90,   90,   89,   89,   88,   88,
+ /*   920 */    88,   87,  335,  430,  318,  124,  212,  163,  856,  856,
+ /*   930 */   943,  900,  898,  833,  118,  759,  726,  725,  257,  755,
+ /*   940 */   289,  289,  733,  734,  961,  833,  119,  682,  311,   93,
+ /*   950 */    82,   84,  868,  871,  860,  860,   91,   91,   92,   92,
+ /*   960 */    92,   92,  430,   90,   90,   90,   90,   89,   89,   88,
+ /*   970 */    88,   88,   87,  335,  430,  716,  246,  322,  331,  856,
+ /*   980 */   856,  256,  114,  357,  833,   53,  808,  913,  913,  932,
+ /*   990 */   156,  416,  420,  424,  930,  809,  833,   34,  364,  311,
+ /*  1000 */   253,   94,   84,  868,  871,  860,  860,   91,   91,   92,
+ /*  1010 */    92,   92,   92,  430,   90,   90,   90,   90,   89,   89,
+ /*  1020 */    88,   88,   88,   87,  335,  430,  114,  114,  114,  960,
+ /*  1030 */   856,  856,  307,  258,  830,  833,  100,  191,  252,  377,
+ /*  1040 */   267,   68,  197,   68,  261,  716,  769,  833,   50,   71,
+ /*  1050 */   911,  911,  263,   84,  868,  871,  860,  860,   91,   91,
+ /*  1060 */    92,   92,   92,   92,  430,   90,   90,   90,   90,   89,
+ /*  1070 */    89,   88,   88,   88,   87,  335,   80,  425,  802,    3,
+ /*  1080 */  1214,  191,  430,  265,  336,  336,  833,  101,  741,   80,
+ /*  1090 */   425,  897,    3,  723,  722,  428,  721,  336,  336,  430,
+ /*  1100 */   893,  270,  430,  197,  833,  102,  430,  800,  428,  430,
+ /*  1110 */   695,  430,  843,  111,  414,  430,  784,  409,  430,  831,
+ /*  1120 */   430,  833,   98,  123,  833,  116,  847,  414,  833,   49,
+ /*  1130 */   779,  833,  113,  833,  106,  226,  123,  833,  105,  847,
+ /*  1140 */   833,  103,  833,  104,  791,  411,   77,   78,  290,  412,
+ /*  1150 */   430,  291,  114,   79,  432,  431,  389,  430,  835,   77,
+ /*  1160 */    78,  897,  839,  408,  410,  430,   79,  432,  431,  372,
+ /*  1170 */   703,  835,  833,   52,  430,   80,  425,  430,    3,  833,
+ /*  1180 */    54,  772,  843,  336,  336,  684,  771,  833,   51,  840,
+ /*  1190 */   840,  840,  842,   19,  428,  672,  833,   26,  671,  833,
+ /*  1200 */    30,  673,  840,  840,  840,  842,   19,  207,  661,  278,
+ /*  1210 */   304,  148,  280,  414,  282,  248,  358,  822,  382,    6,
+ /*  1220 */   348,  161,  273,   80,  425,  847,    3,  934,  895,  720,
+ /*  1230 */   894,  336,  336,  296,  157,  415,  241,  284,  674,  958,
+ /*  1240 */   194,  953,  428,  951,  948,   77,   78,  777,  319,   56,
+ /*  1250 */    59,  135,   79,  432,  431,  121,   66,  835,  146,  128,
+ /*  1260 */   350,  414,  819,  130,  351,  131,  132,  133,  375,  173,
+ /*  1270 */   107,  138,  149,  847,  365,  178,   62,   70,  425,  936,
+ /*  1280 */     3,  827,  889,  371,  255,  336,  336,  792,  840,  840,
+ /*  1290 */   840,  842,   19,   77,   78,  915,  428,  208,  179,  144,
+ /*  1300 */    79,  432,  431,  373,  260,  835,  180,  326,  675,  181,
+ /*  1310 */   308,  744,  388,  743,  731,  414,  718,  742,  730,  712,
+ /*  1320 */   402,  309,  711,  272,  788,   65,  710,  847,  709,  277,
+ /*  1330 */   193,  789,  787,  279,  876,   73,  840,  840,  840,  842,
+ /*  1340 */    19,  786,  281,  418,  283,  422,  227,   77,   78,  330,
+ /*  1350 */   228,  229,   96,  767,   79,  432,  431,  407,   67,  835,
+ /*  1360 */   215,  292,  293,  405,  294,  303,  302,  301,  204,  299,
+ /*  1370 */   295,  202,  676,  681,    7,  433,  669,  203,  205,  206,
+ /*  1380 */   125,  110,  313,  434,  667,  666,  658,  168,  224,  237,
+ /*  1390 */   840,  840,  840,  842,   19,  120,  656,  337,  236,  155,
+ /*  1400 */   167,  341,  233,  314,  108,  905,  903,  826,  127,  126,
+ /*  1410 */   756,  170,  129,  172,  247,  928,  134,  136,  171,   60,
+ /*  1420 */    61,  123,  169,  137,  933,  175,  176,  927,    8,   13,
+ /*  1430 */   177,  254,  918,  139,  191,  924,  140,  370,  678,  150,
+ /*  1440 */   374,  182,  274,  268,  141,  122,   63,   14,  378,   15,
+ /*  1450 */   383,   64,  225,  846,  845,  874,   16,    4,  729,  765,
+ /*  1460 */   770,  162,  395,  209,  211,  142,  801,  878,  796,  312,
+ /*  1470 */    71,   68,  875,  873,  939,  190,  417,  938,   17,  195,
+ /*  1480 */   196,  152,   18,  975,  199,  976,  153,  198,  154,  421,
+ /*  1490 */   877,  844,  696,   81,  200,  297,  343, 1019, 1018,  300,
+ /*  1500 */   653,
+};
+static const YYCODETYPE yy_lookahead[] = {
+ /*     0 */    19,  144,  145,  146,  147,   24,    1,    2,   27,   80,
+ /*    10 */    81,   82,   83,   84,   85,   86,   87,   88,   89,   90,
+ /*    20 */    91,   92,   93,   94,   95,   91,   92,   93,   94,   95,
+ /*    30 */    19,   50,   51,   80,   81,   82,   83,   27,   85,   86,
+ /*    40 */    87,   88,   89,   90,   91,   92,   93,   94,   95,  137,
+ /*    50 */   177,  139,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*    60 */    79,   80,   81,   82,   83,   95,   85,   86,   87,   88,
+ /*    70 */    89,   90,   91,   92,   93,   94,   95,   19,   97,   85,
+ /*    80 */    86,   87,   88,   89,   90,   91,   92,   93,   94,   95,
+ /*    90 */   152,   33,  212,  173,   27,   28,  223,  224,  225,  152,
+ /*   100 */    42,  181,  152,  223,  224,  225,   95,   97,   50,   51,
+ /*   110 */    99,  100,  101,  102,  103,  104,  105,   27,   28,   59,
+ /*   120 */   223,  224,  225,  112,  174,  175,   66,   94,   95,   71,
+ /*   130 */    72,   73,   74,   75,   76,   77,   78,   79,   80,   81,
+ /*   140 */    82,   83,  195,   85,   86,   87,   88,   89,   90,   91,
+ /*   150 */    92,   93,   94,   95,   19,  197,   89,   90,  220,  209,
+ /*   160 */   210,   26,  119,  120,   97,   98,  208,  100,  108,  109,
+ /*   170 */   110,  152,  157,  152,  107,  152,  109,   89,   90,   91,
+ /*   180 */    92,   93,   94,   95,  163,   50,   51,   97,   98,   99,
+ /*   190 */    55,   66,  102,  103,  104,  174,  175,  174,  175,  132,
+ /*   200 */   133,  192,  193,  113,   66,   19,   71,   72,   73,   74,
+ /*   210 */    75,   76,   77,   78,   79,   80,   81,   82,   83,  198,
+ /*   220 */    85,   86,   87,   88,   89,   90,   91,   92,   93,   94,
+ /*   230 */    95,  152,  209,  210,  148,  149,   50,   51,  100,   53,
+ /*   240 */   154,   59,  156,  174,  229,   27,   28,  232,  163,  163,
+ /*   250 */    22,  192,  193,  174,  175,   27,   28,   71,   72,   73,
+ /*   260 */    74,   75,   76,   77,   78,   79,   80,   81,   82,   83,
+ /*   270 */   251,   85,   86,   87,   88,   89,   90,   91,   92,   93,
+ /*   280 */    94,   95,   19,  198,  198,  152,  152,   24,  209,  210,
+ /*   290 */   108,  109,  110,  196,  197,   27,   28,   69,  164,  165,
+ /*   300 */   152,  119,  120,   27,   28,  208,   99,   27,   28,  102,
+ /*   310 */   103,  104,  152,   50,   51,   97,   98,   89,   90,  185,
+ /*   320 */   113,  187,   22,  177,  174,   97,   58,   27,   28,  101,
+ /*   330 */   115,  245,  117,  118,   71,   72,   73,   74,   75,   76,
+ /*   340 */    77,   78,   79,   80,   81,   82,   83,   11,   85,   86,
+ /*   350 */    87,   88,   89,   90,   91,   92,   93,   94,   95,   19,
+ /*   360 */   132,  133,  134,   23,  152,   97,   98,   91,  174,  223,
+ /*   370 */   224,  225,  239,   97,   98,  187,   22,   97,   98,   27,
+ /*   380 */    28,   27,   28,  152,  223,  224,  225,  239,  152,  163,
+ /*   390 */    50,   51,  170,  171,  172,   59,  160,   97,   98,  239,
+ /*   400 */   164,  165,   66,  242,  124,  174,  175,  195,   22,   23,
+ /*   410 */    69,   71,   72,   73,   74,   75,   76,   77,   78,   79,
+ /*   420 */    80,   81,   82,   83,  198,   85,   86,   87,   88,   89,
+ /*   430 */    90,   91,   92,   93,   94,   95,   19,   12,   97,   21,
+ /*   440 */    23,  152,  101,  152,  108,  109,  110,  221,  152,   97,
+ /*   450 */    98,   97,   98,  152,   29,  243,   70,  226,   23,  233,
+ /*   460 */    26,   26,  152,  152,  238,  174,  175,   50,   51,   22,
+ /*   470 */    45,   24,   47,  132,  133,  134,  124,   22,   23,  188,
+ /*   480 */   163,   26,  152,   65,   59,  174,  175,  163,   71,   72,
+ /*   490 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
+ /*   500 */    83,  152,   85,   86,   87,   88,   89,   90,   91,   92,
+ /*   510 */    93,   94,   95,   19,   19,  198,  152,   23,  152,  152,
+ /*   520 */   209,  103,  198,  174,  175,   70,  152,   50,   51,  219,
+ /*   530 */   213,  214,  152,   98,  152,  171,  172,  188,  171,  172,
+ /*   540 */   174,  175,  248,  249,   50,   51,   51,  251,  174,  175,
+ /*   550 */   220,   74,   75,  152,  188,  152,  174,  175,  140,  124,
+ /*   560 */    26,  163,  188,   16,  130,   71,   72,   73,   74,   75,
+ /*   570 */    76,   77,   78,   79,   80,   81,   82,   83,  101,   85,
+ /*   580 */    86,   87,   88,   89,   90,   91,   92,   93,   94,   95,
+ /*   590 */    19,  209,  196,  197,   23,  231,  198,   12,  231,  219,
+ /*   600 */    37,   22,  107,   24,  208,  116,   27,  112,  201,   62,
+ /*   610 */   121,   64,  152,  152,   29,   52,   66,  221,  211,  221,
+ /*   620 */   219,   50,   51,   60,   89,   90,  152,   22,   23,  183,
+ /*   630 */    45,   26,   47,   22,  174,  175,  238,  152,  164,  165,
+ /*   640 */   106,   19,   71,   72,   73,   74,   75,   76,   77,   78,
+ /*   650 */    79,   80,   81,   82,   83,  152,   85,   86,   87,   88,
+ /*   660 */    89,   90,   91,   92,   93,   94,   95,  132,  133,  119,
+ /*   670 */   120,  163,   50,   51,  111,   70,   97,  174,  175,  181,
+ /*   680 */   182,  170,  171,  172,    0,    1,    2,  140,  190,  108,
+ /*   690 */   109,  110,   51,   71,   72,   73,   74,   75,   76,   77,
+ /*   700 */    78,   79,   80,   81,   82,   83,  198,   85,   86,   87,
+ /*   710 */    88,   89,   90,   91,   92,   93,   94,   95,   19,  152,
+ /*   720 */   152,  152,   22,  166,  152,  168,  169,   27,   19,  152,
+ /*   730 */    26,   19,  152,  122,  152,   24,  152,   28,   27,  152,
+ /*   740 */    28,  174,  175,  174,  175,  152,  174,  175,  107,   50,
+ /*   750 */    51,  174,  175,   22,  174,  175,  174,  175,  174,  175,
+ /*   760 */   138,  174,  175,    7,    8,    9,   16,  174,  175,  152,
+ /*   770 */    71,   72,   73,   74,   75,   76,   77,   78,   79,   80,
+ /*   780 */    81,   82,   83,  152,   85,   86,   87,   88,   89,   90,
+ /*   790 */    91,   92,   93,   94,   95,   19,  152,   97,  152,   31,
+ /*   800 */    24,  152,   98,   35,  101,  174,  175,  152,   97,  152,
+ /*   810 */    79,  152,   62,  152,   64,  112,  152,   49,  174,  175,
+ /*   820 */   174,  175,  152,  174,  175,  152,   50,   51,  124,  174,
+ /*   830 */   175,  174,  175,  174,  175,  174,  175,  138,  174,  175,
+ /*   840 */    22,   23,  152,  152,  174,  175,   19,   71,   72,   73,
+ /*   850 */    74,   75,   76,   77,   78,   79,   80,   81,   82,   83,
+ /*   860 */   152,   85,   86,   87,   88,   89,   90,   91,   92,   93,
+ /*   870 */    94,   95,  152,  108,  109,  110,  152,   50,   51,  146,
+ /*   880 */   147,   23,  174,  175,   26,  195,  195,  152,   70,  152,
+ /*   890 */   168,  169,  152,   26,  174,  175,  152,   19,   71,   72,
+ /*   900 */    73,   74,   75,   76,   77,   78,   79,   80,   81,   82,
+ /*   910 */    83,  152,   85,   86,   87,   88,   89,   90,   91,   92,
+ /*   920 */    93,   94,   95,  152,  246,  247,  213,  214,   50,   51,
+ /*   930 */   195,  152,  195,  174,  175,  195,  100,  101,  152,  195,
+ /*   940 */   152,  152,    7,    8,  152,  174,  175,  163,   19,   71,
+ /*   950 */    72,   73,   74,   75,   76,   77,   78,   79,   80,   81,
+ /*   960 */    82,   83,  152,   85,   86,   87,   88,   89,   90,   91,
+ /*   970 */    92,   93,   94,   95,  152,   27,  152,  189,  189,   50,
+ /*   980 */    51,  195,  198,  152,  174,  175,   33,  132,  133,  152,
+ /*   990 */   123,  163,  163,  163,  152,   42,  174,  175,  152,   19,
+ /*  1000 */   152,   72,   73,   74,   75,   76,   77,   78,   79,   80,
+ /*  1010 */    81,   82,   83,  152,   85,   86,   87,   88,   89,   90,
+ /*  1020 */    91,   92,   93,   94,   95,  152,  198,  198,  198,   23,
+ /*  1030 */    50,   51,   26,  152,   23,  174,  175,   26,   23,   23,
+ /*  1040 */    23,   26,   26,   26,  152,   97,   23,  174,  175,   26,
+ /*  1050 */   132,  133,  152,   73,   74,   75,   76,   77,   78,   79,
+ /*  1060 */    80,   81,   82,   83,  152,   85,   86,   87,   88,   89,
+ /*  1070 */    90,   91,   92,   93,   94,   95,   19,   20,   23,   22,
+ /*  1080 */    23,   26,  152,  152,   27,   28,  174,  175,  152,   19,
+ /*  1090 */    20,   27,   22,  183,  183,   38,  152,   27,   28,  152,
+ /*  1100 */    23,  152,  152,   26,  174,  175,  152,  152,   38,  152,
+ /*  1110 */    23,  152,   27,   26,   57,  152,  215,  163,  152,  152,
+ /*  1120 */   152,  174,  175,   66,  174,  175,   69,   57,  174,  175,
+ /*  1130 */   152,  174,  175,  174,  175,  212,   66,  174,  175,   69,
+ /*  1140 */   174,  175,  174,  175,  152,  152,   89,   90,  152,  193,
+ /*  1150 */   152,  152,  198,   96,   97,   98,   91,  152,  101,   89,
+ /*  1160 */    90,   97,  152,  209,  210,  152,   96,   97,   98,  235,
+ /*  1170 */   152,  101,  174,  175,  152,   19,   20,  152,   22,  174,
+ /*  1180 */   175,  116,   97,   27,   28,  152,  121,  174,  175,  132,
+ /*  1190 */   133,  134,  135,  136,   38,  152,  174,  175,  152,  174,
+ /*  1200 */   175,  152,  132,  133,  134,  135,  136,  234,  152,  212,
+ /*  1210 */   150,  199,  212,   57,  212,  240,  240,  203,  178,  200,
+ /*  1220 */   216,  186,  177,   19,   20,   69,   22,  203,  177,  182,
+ /*  1230 */   177,   27,   28,  202,  200,  228,  216,  216,  155,   39,
+ /*  1240 */   122,  159,   38,  159,   41,   89,   90,   91,  159,  241,
+ /*  1250 */   241,   22,   96,   97,   98,   71,  130,  101,  222,  191,
+ /*  1260 */    18,   57,  203,  194,  159,  194,  194,  194,   18,  158,
+ /*  1270 */   244,  191,  222,   69,  159,  158,  137,   19,   20,  203,
+ /*  1280 */    22,  191,  203,   46,  236,   27,   28,  159,  132,  133,
+ /*  1290 */   134,  135,  136,   89,   90,  237,   38,  159,  158,   22,
+ /*  1300 */    96,   97,   98,  179,  159,  101,  158,   48,  159,  158,
+ /*  1310 */   179,  176,  107,  176,  184,   57,  106,  176,  184,  176,
+ /*  1320 */   125,  179,  178,  176,  218,  107,  176,   69,  176,  217,
+ /*  1330 */   159,  218,  218,  217,  159,  137,  132,  133,  134,  135,
+ /*  1340 */   136,  218,  217,  179,  217,  179,  227,   89,   90,   95,
+ /*  1350 */   230,  230,  129,  207,   96,   97,   98,  126,  128,  101,
+ /*  1360 */     5,  206,  205,  127,  204,   10,   11,   12,   13,   14,
+ /*  1370 */   203,   25,   17,  162,   26,  161,   13,  153,  153,    6,
+ /*  1380 */   247,  180,  250,  151,  151,  151,  151,   32,  180,   34,
+ /*  1390 */   132,  133,  134,  135,  136,  167,    4,    3,   43,   22,
+ /*  1400 */    15,   68,  142,  250,   16,   23,   23,  120,  111,  131,
+ /*  1410 */    20,   56,  123,  125,   16,    1,  123,  131,   63,   79,
+ /*  1420 */    79,   66,   67,  111,   28,   36,  122,    1,    5,   22,
+ /*  1430 */   107,  140,   54,   54,   26,   61,  107,   44,   20,   24,
+ /*  1440 */    19,  105,  112,   23,   22,   40,   22,   22,   53,   22,
+ /*  1450 */    53,   22,   53,   23,   23,   23,   22,   22,   30,  116,
+ /*  1460 */    23,  122,   26,   23,   23,   22,   28,   11,  124,  114,
+ /*  1470 */    26,   26,   23,   23,   23,   36,   24,   23,   36,   26,
+ /*  1480 */    22,   22,   36,   23,  122,   23,   22,   26,   22,   24,
+ /*  1490 */    23,   23,   23,   22,  122,   23,  141,  122,  122,   15,
+ /*  1500 */     1,
+};
+#define YY_SHIFT_USE_DFLT (-89)
+#define YY_SHIFT_COUNT (435)
+#define YY_SHIFT_MIN   (-88)
+#define YY_SHIFT_MAX   (1499)
+static const short yy_shift_ofst[] = {
+ /*     0 */     5, 1057, 1355, 1070, 1204, 1204, 1204,   90,   60,  -19,
+ /*    10 */    58,   58,  186, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
+ /*    20 */    67,   67,  182,  336,  218,  550,  135,  263,  340,  417,
+ /*    30 */   494,  571,  622,  699,  776,  827,  827,  827,  827,  827,
+ /*    40 */   827,  827,  827,  827,  827,  827,  827,  827,  827,  827,
+ /*    50 */   878,  827,  929,  980,  980, 1156, 1204, 1204, 1204, 1204,
+ /*    60 */  1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
+ /*    70 */  1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,
+ /*    80 */  1204, 1204, 1204, 1204, 1258, 1204, 1204, 1204, 1204, 1204,
+ /*    90 */  1204, 1204, 1204, 1204, 1204, 1204, 1204, 1204,  -71,  -47,
+ /*   100 */   -47,  -47,  -47,  -47,   -6,   88,  -66,  218,  218,  418,
+ /*   110 */   495,  535,  535,   33,   43,   10,  -30,  -89,  -89,  -89,
+ /*   120 */    11,  425,  425,  268,  455,  605,  218,  218,  218,  218,
+ /*   130 */   218,  218,  218,  218,  218,  218,  218,  218,  218,  218,
+ /*   140 */   218,  218,  218,  218,  218,  684,  138,   10,   43,  125,
+ /*   150 */   125,  125,  125,  125,  125,  -89,  -89,  -89,  228,  341,
+ /*   160 */   341,  207,  276,  300,  280,  352,  354,  218,  218,  218,
+ /*   170 */   218,  218,  218,  218,  218,  218,  218,  218,  218,  218,
+ /*   180 */   218,  218,  218,  218,  563,  563,  563,  218,  218,  435,
+ /*   190 */   218,  218,  218,  579,  218,  218,  585,  218,  218,  218,
+ /*   200 */   218,  218,  218,  218,  218,  218,  218,  581,  768,  711,
+ /*   210 */   711,  711,  704,  215, 1065,  756,  434,  709,  709,  712,
+ /*   220 */   434,  712,  534,  858,  641,  953,  709,  -88,  953,  953,
+ /*   230 */   867,  489,  447, 1200, 1118, 1118, 1203, 1203, 1118, 1229,
+ /*   240 */  1184, 1126, 1242, 1242, 1242, 1242, 1118, 1250, 1126, 1229,
+ /*   250 */  1184, 1184, 1126, 1118, 1250, 1139, 1237, 1118, 1118, 1250,
+ /*   260 */  1277, 1118, 1250, 1118, 1250, 1277, 1205, 1205, 1205, 1259,
+ /*   270 */  1277, 1205, 1210, 1205, 1259, 1205, 1205, 1195, 1218, 1195,
+ /*   280 */  1218, 1195, 1218, 1195, 1218, 1118, 1118, 1198, 1277, 1254,
+ /*   290 */  1254, 1277, 1223, 1231, 1230, 1236, 1126, 1346, 1348, 1363,
+ /*   300 */  1363, 1373, 1373, 1373, 1373,  -89,  -89,  -89,  -89,  -89,
+ /*   310 */   -89,  477,  547,  386,  818,  750,  765,  700, 1006,  731,
+ /*   320 */  1011, 1015, 1016, 1017,  948,  836,  935,  703, 1023, 1055,
+ /*   330 */  1064, 1077,  855,  918, 1087, 1085,  611, 1392, 1394, 1377,
+ /*   340 */  1260, 1385, 1333, 1388, 1382, 1383, 1287, 1278, 1297, 1289,
+ /*   350 */  1390, 1288, 1398, 1414, 1293, 1286, 1340, 1341, 1312, 1396,
+ /*   360 */  1389, 1304, 1426, 1423, 1407, 1323, 1291, 1378, 1408, 1379,
+ /*   370 */  1374, 1393, 1329, 1415, 1418, 1421, 1330, 1336, 1422, 1395,
+ /*   380 */  1424, 1425, 1420, 1427, 1397, 1428, 1429, 1399, 1405, 1430,
+ /*   390 */  1431, 1432, 1343, 1434, 1437, 1435, 1436, 1339, 1440, 1441,
+ /*   400 */  1438, 1439, 1443, 1344, 1444, 1442, 1445, 1446, 1444, 1449,
+ /*   410 */  1450, 1451, 1453, 1454, 1458, 1456, 1460, 1459, 1452, 1461,
+ /*   420 */  1462, 1464, 1465, 1461, 1467, 1466, 1468, 1469, 1471, 1362,
+ /*   430 */  1372, 1375, 1376, 1472, 1484, 1499,
+};
+#define YY_REDUCE_USE_DFLT (-144)
+#define YY_REDUCE_COUNT (310)
+#define YY_REDUCE_MIN   (-143)
+#define YY_REDUCE_MAX   (1235)
+static const short yy_reduce_ofst[] = {
+ /*     0 */  -143,  954,   86,   21,  -50,   23,   79,  134,  226, -120,
+ /*    10 */  -127,  146,  161,  291,  349,  366,  311,  382,  374,  231,
+ /*    20 */   364,  367,  396,  398,  236,  317, -103, -103, -103, -103,
+ /*    30 */  -103, -103, -103, -103, -103, -103, -103, -103, -103, -103,
+ /*    40 */  -103, -103, -103, -103, -103, -103, -103, -103, -103, -103,
+ /*    50 */  -103, -103, -103, -103, -103,  460,  503,  567,  569,  572,
+ /*    60 */   577,  580,  582,  584,  587,  593,  631,  644,  646,  649,
+ /*    70 */   655,  657,  659,  661,  664,  670,  708,  720,  759,  771,
+ /*    80 */   810,  822,  861,  873,  912,  930,  947,  950,  957,  959,
+ /*    90 */   963,  966,  968,  998, 1005, 1013, 1022, 1025, -103, -103,
+ /*   100 */  -103, -103, -103, -103, -103, -103, -103,  474,  212,   15,
+ /*   110 */   498,  222,  511, -103,   97,  557, -103, -103, -103, -103,
+ /*   120 */   -80,    9,   59,   19,  294,  294,  -53,  -62,  690,  691,
+ /*   130 */   735,  737,  740,  744,  133,  310,  148,  330,  160,  380,
+ /*   140 */   786,  788,  401,  296,  789,  733,   85,  722,  -42,  324,
+ /*   150 */   508,  784,  828,  829,  830,  678,  713,  407,   69,  150,
+ /*   160 */   194,  188,  289,  301,  403,  461,  485,  568,  617,  673,
+ /*   170 */   724,  779,  792,  824,  831,  837,  842,  846,  848,  881,
+ /*   180 */   892,  900,  931,  936,  446,  910,  911,  944,  949,  901,
+ /*   190 */   955,  967,  978,  923,  992,  993,  956,  996,  999, 1010,
+ /*   200 */   289, 1018, 1033, 1043, 1046, 1049, 1056,  934,  973,  997,
+ /*   210 */  1000, 1002,  901, 1012, 1019, 1060, 1014, 1004, 1020,  975,
+ /*   220 */  1024,  976, 1040, 1035, 1047, 1045, 1021, 1007, 1051, 1053,
+ /*   230 */  1031, 1034, 1083, 1026, 1082, 1084, 1008, 1009, 1089, 1036,
+ /*   240 */  1068, 1059, 1069, 1071, 1072, 1073, 1105, 1111, 1076, 1050,
+ /*   250 */  1080, 1090, 1079, 1115, 1117, 1058, 1048, 1128, 1138, 1140,
+ /*   260 */  1124, 1145, 1148, 1149, 1151, 1131, 1135, 1137, 1141, 1130,
+ /*   270 */  1142, 1143, 1144, 1147, 1134, 1150, 1152, 1106, 1112, 1113,
+ /*   280 */  1116, 1114, 1125, 1123, 1127, 1171, 1175, 1119, 1164, 1120,
+ /*   290 */  1121, 1166, 1146, 1155, 1157, 1160, 1167, 1211, 1214, 1224,
+ /*   300 */  1225, 1232, 1233, 1234, 1235, 1132, 1153, 1133, 1201, 1208,
+ /*   310 */  1228,
+};
+static const YYACTIONTYPE yy_default[] = {
+ /*     0 */   982, 1300, 1300, 1300, 1214, 1214, 1214, 1305, 1300, 1109,
+ /*    10 */  1138, 1138, 1274, 1305, 1305, 1305, 1305, 1305, 1305, 1212,
+ /*    20 */  1305, 1305, 1305, 1300, 1305, 1113, 1144, 1305, 1305, 1305,
+ /*    30 */  1305, 1305, 1305, 1305, 1305, 1273, 1275, 1152, 1151, 1254,
+ /*    40 */  1125, 1149, 1142, 1146, 1215, 1208, 1209, 1207, 1211, 1216,
+ /*    50 */  1305, 1145, 1177, 1192, 1176, 1305, 1305, 1305, 1305, 1305,
+ /*    60 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*    70 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*    80 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*    90 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1186, 1191,
+ /*   100 */  1198, 1190, 1187, 1179, 1178, 1180, 1181, 1305, 1305, 1008,
+ /*   110 */  1074, 1305, 1305, 1182, 1305, 1020, 1183, 1195, 1194, 1193,
+ /*   120 */  1015, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   130 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   140 */  1305, 1305, 1305, 1305, 1305,  982, 1300, 1305, 1305, 1300,
+ /*   150 */  1300, 1300, 1300, 1300, 1300, 1292, 1113, 1103, 1305, 1305,
+ /*   160 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1280, 1278,
+ /*   170 */  1305, 1227, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   180 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   190 */  1305, 1305, 1305, 1109, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   200 */  1305, 1305, 1305, 1305, 1305, 1305,  988, 1305, 1247, 1109,
+ /*   210 */  1109, 1109, 1111, 1089, 1101,  990, 1148, 1127, 1127, 1259,
+ /*   220 */  1148, 1259, 1045, 1068, 1042, 1138, 1127, 1210, 1138, 1138,
+ /*   230 */  1110, 1101, 1305, 1285, 1118, 1118, 1277, 1277, 1118, 1157,
+ /*   240 */  1078, 1148, 1085, 1085, 1085, 1085, 1118, 1005, 1148, 1157,
+ /*   250 */  1078, 1078, 1148, 1118, 1005, 1253, 1251, 1118, 1118, 1005,
+ /*   260 */  1220, 1118, 1005, 1118, 1005, 1220, 1076, 1076, 1076, 1060,
+ /*   270 */  1220, 1076, 1045, 1076, 1060, 1076, 1076, 1131, 1126, 1131,
+ /*   280 */  1126, 1131, 1126, 1131, 1126, 1118, 1118, 1305, 1220, 1224,
+ /*   290 */  1224, 1220, 1143, 1132, 1141, 1139, 1148, 1011, 1063,  998,
+ /*   300 */   998,  987,  987,  987,  987, 1297, 1297, 1292, 1047, 1047,
+ /*   310 */  1030, 1305, 1305, 1305, 1305, 1305, 1305, 1022, 1305, 1229,
+ /*   320 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   330 */  1305, 1305, 1305, 1305, 1305, 1305, 1164, 1305,  983, 1287,
+ /*   340 */  1305, 1305, 1284, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   350 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   360 */  1305, 1257, 1305, 1305, 1305, 1305, 1305, 1305, 1250, 1249,
+ /*   370 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   380 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305,
+ /*   390 */  1305, 1305, 1092, 1305, 1305, 1305, 1096, 1305, 1305, 1305,
+ /*   400 */  1305, 1305, 1305, 1305, 1140, 1305, 1133, 1305, 1213, 1305,
+ /*   410 */  1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1305, 1302,
+ /*   420 */  1305, 1305, 1305, 1301, 1305, 1305, 1305, 1305, 1305, 1166,
+ /*   430 */  1305, 1165, 1169, 1305,  996, 1305,
+};
+/********** End of lemon-generated parsing tables *****************************/
+
+/* The next table maps tokens (terminal symbols) into fallback tokens.  
+** If a construct like the following:
+** 
+**      %fallback ID X Y Z.
+**
+** appears in the grammar, then ID becomes a fallback token for X, Y,
+** and Z.  Whenever one of the tokens X, Y, or Z is input to the parser
+** but it does not parse, the type of the token is changed to ID and
+** the parse is retried before an error is thrown.
+**
+** This feature can be used, for example, to cause some keywords in a language
+** to revert to identifiers if they keyword does not apply in the context where
+** it appears.
+*/
+#ifdef YYFALLBACK
+static const YYCODETYPE yyFallback[] = {
+    0,  /*          $ => nothing */
+    0,  /*       SEMI => nothing */
+   27,  /*    EXPLAIN => ID */
+   27,  /*      QUERY => ID */
+   27,  /*       PLAN => ID */
+   27,  /*      BEGIN => ID */
+    0,  /* TRANSACTION => nothing */
+   27,  /*   DEFERRED => ID */
+   27,  /*  IMMEDIATE => ID */
+   27,  /*  EXCLUSIVE => ID */
+    0,  /*     COMMIT => nothing */
+   27,  /*        END => ID */
+   27,  /*   ROLLBACK => ID */
+   27,  /*  SAVEPOINT => ID */
+   27,  /*    RELEASE => ID */
+    0,  /*         TO => nothing */
+    0,  /*      TABLE => nothing */
+    0,  /*     CREATE => nothing */
+   27,  /*         IF => ID */
+    0,  /*        NOT => nothing */
+    0,  /*     EXISTS => nothing */
+   27,  /*       TEMP => ID */
+    0,  /*         LP => nothing */
+    0,  /*         RP => nothing */
+    0,  /*         AS => nothing */
+   27,  /*    WITHOUT => ID */
+    0,  /*      COMMA => nothing */
+    0,  /*         ID => nothing */
+    0,  /*    INDEXED => nothing */
+   27,  /*      ABORT => ID */
+   27,  /*     ACTION => ID */
+   27,  /*      AFTER => ID */
+   27,  /*    ANALYZE => ID */
+   27,  /*        ASC => ID */
+   27,  /*     ATTACH => ID */
+   27,  /*     BEFORE => ID */
+   27,  /*         BY => ID */
+   27,  /*    CASCADE => ID */
+   27,  /*       CAST => ID */
+   27,  /*   COLUMNKW => ID */
+   27,  /*   CONFLICT => ID */
+   27,  /*   DATABASE => ID */
+   27,  /*       DESC => ID */
+   27,  /*     DETACH => ID */
+   27,  /*       EACH => ID */
+   27,  /*       FAIL => ID */
+   27,  /*        FOR => ID */
+   27,  /*     IGNORE => ID */
+   27,  /*  INITIALLY => ID */
+   27,  /*    INSTEAD => ID */
+   27,  /*    LIKE_KW => ID */
+   27,  /*      MATCH => ID */
+   27,  /*         NO => ID */
+   27,  /*        KEY => ID */
+   27,  /*         OF => ID */
+   27,  /*     OFFSET => ID */
+   27,  /*     PRAGMA => ID */
+   27,  /*      RAISE => ID */
+   27,  /*  RECURSIVE => ID */
+   27,  /*    REPLACE => ID */
+   27,  /*   RESTRICT => ID */
+   27,  /*        ROW => ID */
+   27,  /*    TRIGGER => ID */
+   27,  /*     VACUUM => ID */
+   27,  /*       VIEW => ID */
+   27,  /*    VIRTUAL => ID */
+   27,  /*       WITH => ID */
+   27,  /*    REINDEX => ID */
+   27,  /*     RENAME => ID */
+   27,  /*   CTIME_KW => ID */
+};
+#endif /* YYFALLBACK */
+
+/* The following structure represents a single element of the
+** parser's stack.  Information stored includes:
+**
+**   +  The state number for the parser at this level of the stack.
+**
+**   +  The value of the token stored at this level of the stack.
+**      (In other words, the "major" token.)
+**
+**   +  The semantic value stored at this level of the stack.  This is
+**      the information used by the action routines in the grammar.
+**      It is sometimes called the "minor" token.
+**
+** After the "shift" half of a SHIFTREDUCE action, the stateno field
+** actually contains the reduce action for the second half of the
+** SHIFTREDUCE.
+*/
+struct yyStackEntry {
+  YYACTIONTYPE stateno;  /* The state-number, or reduce action in SHIFTREDUCE */
+  YYCODETYPE major;      /* The major token value.  This is the code
+                         ** number for the token at this stack level */
+  YYMINORTYPE minor;     /* The user-supplied minor token value.  This
+                         ** is the value of the token  */
+};
+typedef struct yyStackEntry yyStackEntry;
+
+/* The state of the parser is completely contained in an instance of
+** the following structure */
+struct yyParser {
+  int yyidx;                    /* Index of top element in stack */
+#ifdef YYTRACKMAXSTACKDEPTH
+  int yyidxMax;                 /* Maximum value of yyidx */
+#endif
+  int yyerrcnt;                 /* Shifts left before out of the error */
+  sqlite3ParserARG_SDECL                /* A place to hold %extra_argument */
+#if YYSTACKDEPTH<=0
+  int yystksz;                  /* Current side of the stack */
+  yyStackEntry *yystack;        /* The parser's stack */
+#else
+  yyStackEntry yystack[YYSTACKDEPTH];  /* The parser's stack */
+#endif
+};
+typedef struct yyParser yyParser;
+
+#ifndef NDEBUG
+/* #include <stdio.h> */
+static FILE *yyTraceFILE = 0;
+static char *yyTracePrompt = 0;
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* 
+** Turn parser tracing on by giving a stream to which to write the trace
+** and a prompt to preface each trace message.  Tracing is turned off
+** by making either argument NULL 
+**
+** Inputs:
+** <ul>
+** <li> A FILE* to which trace output should be written.
+**      If NULL, then tracing is turned off.
+** <li> A prefix string written at the beginning of every
+**      line of trace output.  If NULL, then tracing is
+**      turned off.
+** </ul>
+**
+** Outputs:
+** None.
+*/
+SQLITE_PRIVATE void sqlite3ParserTrace(FILE *TraceFILE, char *zTracePrompt){
+  yyTraceFILE = TraceFILE;
+  yyTracePrompt = zTracePrompt;
+  if( yyTraceFILE==0 ) yyTracePrompt = 0;
+  else if( yyTracePrompt==0 ) yyTraceFILE = 0;
+}
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing shifts, the names of all terminals and nonterminals
+** are required.  The following table supplies these names */
+static const char *const yyTokenName[] = { 
+  "$",             "SEMI",          "EXPLAIN",       "QUERY",       
+  "PLAN",          "BEGIN",         "TRANSACTION",   "DEFERRED",    
+  "IMMEDIATE",     "EXCLUSIVE",     "COMMIT",        "END",         
+  "ROLLBACK",      "SAVEPOINT",     "RELEASE",       "TO",          
+  "TABLE",         "CREATE",        "IF",            "NOT",         
+  "EXISTS",        "TEMP",          "LP",            "RP",          
+  "AS",            "WITHOUT",       "COMMA",         "ID",          
+  "INDEXED",       "ABORT",         "ACTION",        "AFTER",       
+  "ANALYZE",       "ASC",           "ATTACH",        "BEFORE",      
+  "BY",            "CASCADE",       "CAST",          "COLUMNKW",    
+  "CONFLICT",      "DATABASE",      "DESC",          "DETACH",      
+  "EACH",          "FAIL",          "FOR",           "IGNORE",      
+  "INITIALLY",     "INSTEAD",       "LIKE_KW",       "MATCH",       
+  "NO",            "KEY",           "OF",            "OFFSET",      
+  "PRAGMA",        "RAISE",         "RECURSIVE",     "REPLACE",     
+  "RESTRICT",      "ROW",           "TRIGGER",       "VACUUM",      
+  "VIEW",          "VIRTUAL",       "WITH",          "REINDEX",     
+  "RENAME",        "CTIME_KW",      "ANY",           "OR",          
+  "AND",           "IS",            "BETWEEN",       "IN",          
+  "ISNULL",        "NOTNULL",       "NE",            "EQ",          
+  "GT",            "LE",            "LT",            "GE",          
+  "ESCAPE",        "BITAND",        "BITOR",         "LSHIFT",      
+  "RSHIFT",        "PLUS",          "MINUS",         "STAR",        
+  "SLASH",         "REM",           "CONCAT",        "COLLATE",     
+  "BITNOT",        "STRING",        "JOIN_KW",       "CONSTRAINT",  
+  "DEFAULT",       "NULL",          "PRIMARY",       "UNIQUE",      
+  "CHECK",         "REFERENCES",    "AUTOINCR",      "ON",          
+  "INSERT",        "DELETE",        "UPDATE",        "SET",         
+  "DEFERRABLE",    "FOREIGN",       "DROP",          "UNION",       
+  "ALL",           "EXCEPT",        "INTERSECT",     "SELECT",      
+  "VALUES",        "DISTINCT",      "DOT",           "FROM",        
+  "JOIN",          "USING",         "ORDER",         "GROUP",       
+  "HAVING",        "LIMIT",         "WHERE",         "INTO",        
+  "INTEGER",       "FLOAT",         "BLOB",          "VARIABLE",    
+  "CASE",          "WHEN",          "THEN",          "ELSE",        
+  "INDEX",         "ALTER",         "ADD",           "error",       
+  "input",         "cmdlist",       "ecmd",          "explain",     
+  "cmdx",          "cmd",           "transtype",     "trans_opt",   
+  "nm",            "savepoint_opt",  "create_table",  "create_table_args",
+  "createkw",      "temp",          "ifnotexists",   "dbnm",        
+  "columnlist",    "conslist_opt",  "table_options",  "select",      
+  "column",        "columnid",      "type",          "carglist",    
+  "typetoken",     "typename",      "signed",        "plus_num",    
+  "minus_num",     "ccons",         "term",          "expr",        
+  "onconf",        "sortorder",     "autoinc",       "eidlist_opt", 
+  "refargs",       "defer_subclause",  "refarg",        "refact",      
+  "init_deferred_pred_opt",  "conslist",      "tconscomma",    "tcons",       
+  "sortlist",      "eidlist",       "defer_subclause_opt",  "orconf",      
+  "resolvetype",   "raisetype",     "ifexists",      "fullname",    
+  "selectnowith",  "oneselect",     "with",          "multiselect_op",
+  "distinct",      "selcollist",    "from",          "where_opt",   
+  "groupby_opt",   "having_opt",    "orderby_opt",   "limit_opt",   
+  "values",        "nexprlist",     "exprlist",      "sclp",        
+  "as",            "seltablist",    "stl_prefix",    "joinop",      
+  "indexed_opt",   "on_opt",        "using_opt",     "idlist",      
+  "setlist",       "insert_cmd",    "idlist_opt",    "likeop",      
+  "between_op",    "in_op",         "case_operand",  "case_exprlist",
+  "case_else",     "uniqueflag",    "collate",       "nmnum",       
+  "trigger_decl",  "trigger_cmd_list",  "trigger_time",  "trigger_event",
+  "foreach_clause",  "when_clause",   "trigger_cmd",   "trnm",        
+  "tridxby",       "database_kw_opt",  "key_opt",       "add_column_fullname",
+  "kwcolumn_opt",  "create_vtab",   "vtabarglist",   "vtabarg",     
+  "vtabargtoken",  "lp",            "anylist",       "wqlist",      
+};
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+/* For tracing reduce actions, the names of all rules are required.
+*/
+static const char *const yyRuleName[] = {
+ /*   0 */ "input ::= cmdlist",
+ /*   1 */ "cmdlist ::= cmdlist ecmd",
+ /*   2 */ "cmdlist ::= ecmd",
+ /*   3 */ "ecmd ::= SEMI",
+ /*   4 */ "ecmd ::= explain cmdx SEMI",
+ /*   5 */ "explain ::=",
+ /*   6 */ "explain ::= EXPLAIN",
+ /*   7 */ "explain ::= EXPLAIN QUERY PLAN",
+ /*   8 */ "cmdx ::= cmd",
+ /*   9 */ "cmd ::= BEGIN transtype trans_opt",
+ /*  10 */ "trans_opt ::=",
+ /*  11 */ "trans_opt ::= TRANSACTION",
+ /*  12 */ "trans_opt ::= TRANSACTION nm",
+ /*  13 */ "transtype ::=",
+ /*  14 */ "transtype ::= DEFERRED",
+ /*  15 */ "transtype ::= IMMEDIATE",
+ /*  16 */ "transtype ::= EXCLUSIVE",
+ /*  17 */ "cmd ::= COMMIT trans_opt",
+ /*  18 */ "cmd ::= END trans_opt",
+ /*  19 */ "cmd ::= ROLLBACK trans_opt",
+ /*  20 */ "savepoint_opt ::= SAVEPOINT",
+ /*  21 */ "savepoint_opt ::=",
+ /*  22 */ "cmd ::= SAVEPOINT nm",
+ /*  23 */ "cmd ::= RELEASE savepoint_opt nm",
+ /*  24 */ "cmd ::= ROLLBACK trans_opt TO savepoint_opt nm",
+ /*  25 */ "cmd ::= create_table create_table_args",
+ /*  26 */ "create_table ::= createkw temp TABLE ifnotexists nm dbnm",
+ /*  27 */ "createkw ::= CREATE",
+ /*  28 */ "ifnotexists ::=",
+ /*  29 */ "ifnotexists ::= IF NOT EXISTS",
+ /*  30 */ "temp ::= TEMP",
+ /*  31 */ "temp ::=",
+ /*  32 */ "create_table_args ::= LP columnlist conslist_opt RP table_options",
+ /*  33 */ "create_table_args ::= AS select",
+ /*  34 */ "table_options ::=",
+ /*  35 */ "table_options ::= WITHOUT nm",
+ /*  36 */ "columnlist ::= columnlist COMMA column",
+ /*  37 */ "columnlist ::= column",
+ /*  38 */ "column ::= columnid type carglist",
+ /*  39 */ "columnid ::= nm",
+ /*  40 */ "nm ::= ID|INDEXED",
+ /*  41 */ "nm ::= STRING",
+ /*  42 */ "nm ::= JOIN_KW",
+ /*  43 */ "type ::=",
+ /*  44 */ "type ::= typetoken",
+ /*  45 */ "typetoken ::= typename",
+ /*  46 */ "typetoken ::= typename LP signed RP",
+ /*  47 */ "typetoken ::= typename LP signed COMMA signed RP",
+ /*  48 */ "typename ::= ID|STRING",
+ /*  49 */ "typename ::= typename ID|STRING",
+ /*  50 */ "signed ::= plus_num",
+ /*  51 */ "signed ::= minus_num",
+ /*  52 */ "carglist ::= carglist ccons",
+ /*  53 */ "carglist ::=",
+ /*  54 */ "ccons ::= CONSTRAINT nm",
+ /*  55 */ "ccons ::= DEFAULT term",
+ /*  56 */ "ccons ::= DEFAULT LP expr RP",
+ /*  57 */ "ccons ::= DEFAULT PLUS term",
+ /*  58 */ "ccons ::= DEFAULT MINUS term",
+ /*  59 */ "ccons ::= DEFAULT ID|INDEXED",
+ /*  60 */ "ccons ::= NULL onconf",
+ /*  61 */ "ccons ::= NOT NULL onconf",
+ /*  62 */ "ccons ::= PRIMARY KEY sortorder onconf autoinc",
+ /*  63 */ "ccons ::= UNIQUE onconf",
+ /*  64 */ "ccons ::= CHECK LP expr RP",
+ /*  65 */ "ccons ::= REFERENCES nm eidlist_opt refargs",
+ /*  66 */ "ccons ::= defer_subclause",
+ /*  67 */ "ccons ::= COLLATE ID|STRING",
+ /*  68 */ "autoinc ::=",
+ /*  69 */ "autoinc ::= AUTOINCR",
+ /*  70 */ "refargs ::=",
+ /*  71 */ "refargs ::= refargs refarg",
+ /*  72 */ "refarg ::= MATCH nm",
+ /*  73 */ "refarg ::= ON INSERT refact",
+ /*  74 */ "refarg ::= ON DELETE refact",
+ /*  75 */ "refarg ::= ON UPDATE refact",
+ /*  76 */ "refact ::= SET NULL",
+ /*  77 */ "refact ::= SET DEFAULT",
+ /*  78 */ "refact ::= CASCADE",
+ /*  79 */ "refact ::= RESTRICT",
+ /*  80 */ "refact ::= NO ACTION",
+ /*  81 */ "defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt",
+ /*  82 */ "defer_subclause ::= DEFERRABLE init_deferred_pred_opt",
+ /*  83 */ "init_deferred_pred_opt ::=",
+ /*  84 */ "init_deferred_pred_opt ::= INITIALLY DEFERRED",
+ /*  85 */ "init_deferred_pred_opt ::= INITIALLY IMMEDIATE",
+ /*  86 */ "conslist_opt ::=",
+ /*  87 */ "conslist_opt ::= COMMA conslist",
+ /*  88 */ "conslist ::= conslist tconscomma tcons",
+ /*  89 */ "conslist ::= tcons",
+ /*  90 */ "tconscomma ::= COMMA",
+ /*  91 */ "tconscomma ::=",
+ /*  92 */ "tcons ::= CONSTRAINT nm",
+ /*  93 */ "tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf",
+ /*  94 */ "tcons ::= UNIQUE LP sortlist RP onconf",
+ /*  95 */ "tcons ::= CHECK LP expr RP onconf",
+ /*  96 */ "tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt",
+ /*  97 */ "defer_subclause_opt ::=",
+ /*  98 */ "defer_subclause_opt ::= defer_subclause",
+ /*  99 */ "onconf ::=",
+ /* 100 */ "onconf ::= ON CONFLICT resolvetype",
+ /* 101 */ "orconf ::=",
+ /* 102 */ "orconf ::= OR resolvetype",
+ /* 103 */ "resolvetype ::= raisetype",
+ /* 104 */ "resolvetype ::= IGNORE",
+ /* 105 */ "resolvetype ::= REPLACE",
+ /* 106 */ "cmd ::= DROP TABLE ifexists fullname",
+ /* 107 */ "ifexists ::= IF EXISTS",
+ /* 108 */ "ifexists ::=",
+ /* 109 */ "cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select",
+ /* 110 */ "cmd ::= DROP VIEW ifexists fullname",
+ /* 111 */ "cmd ::= select",
+ /* 112 */ "select ::= with selectnowith",
+ /* 113 */ "selectnowith ::= oneselect",
+ /* 114 */ "selectnowith ::= selectnowith multiselect_op oneselect",
+ /* 115 */ "multiselect_op ::= UNION",
+ /* 116 */ "multiselect_op ::= UNION ALL",
+ /* 117 */ "multiselect_op ::= EXCEPT|INTERSECT",
+ /* 118 */ "oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt",
+ /* 119 */ "oneselect ::= values",
+ /* 120 */ "values ::= VALUES LP nexprlist RP",
+ /* 121 */ "values ::= values COMMA LP exprlist RP",
+ /* 122 */ "distinct ::= DISTINCT",
+ /* 123 */ "distinct ::= ALL",
+ /* 124 */ "distinct ::=",
+ /* 125 */ "sclp ::= selcollist COMMA",
+ /* 126 */ "sclp ::=",
+ /* 127 */ "selcollist ::= sclp expr as",
+ /* 128 */ "selcollist ::= sclp STAR",
+ /* 129 */ "selcollist ::= sclp nm DOT STAR",
+ /* 130 */ "as ::= AS nm",
+ /* 131 */ "as ::= ID|STRING",
+ /* 132 */ "as ::=",
+ /* 133 */ "from ::=",
+ /* 134 */ "from ::= FROM seltablist",
+ /* 135 */ "stl_prefix ::= seltablist joinop",
+ /* 136 */ "stl_prefix ::=",
+ /* 137 */ "seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt",
+ /* 138 */ "seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt",
+ /* 139 */ "seltablist ::= stl_prefix LP select RP as on_opt using_opt",
+ /* 140 */ "seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt",
+ /* 141 */ "dbnm ::=",
+ /* 142 */ "dbnm ::= DOT nm",
+ /* 143 */ "fullname ::= nm dbnm",
+ /* 144 */ "joinop ::= COMMA|JOIN",
+ /* 145 */ "joinop ::= JOIN_KW JOIN",
+ /* 146 */ "joinop ::= JOIN_KW nm JOIN",
+ /* 147 */ "joinop ::= JOIN_KW nm nm JOIN",
+ /* 148 */ "on_opt ::= ON expr",
+ /* 149 */ "on_opt ::=",
+ /* 150 */ "indexed_opt ::=",
+ /* 151 */ "indexed_opt ::= INDEXED BY nm",
+ /* 152 */ "indexed_opt ::= NOT INDEXED",
+ /* 153 */ "using_opt ::= USING LP idlist RP",
+ /* 154 */ "using_opt ::=",
+ /* 155 */ "orderby_opt ::=",
+ /* 156 */ "orderby_opt ::= ORDER BY sortlist",
+ /* 157 */ "sortlist ::= sortlist COMMA expr sortorder",
+ /* 158 */ "sortlist ::= expr sortorder",
+ /* 159 */ "sortorder ::= ASC",
+ /* 160 */ "sortorder ::= DESC",
+ /* 161 */ "sortorder ::=",
+ /* 162 */ "groupby_opt ::=",
+ /* 163 */ "groupby_opt ::= GROUP BY nexprlist",
+ /* 164 */ "having_opt ::=",
+ /* 165 */ "having_opt ::= HAVING expr",
+ /* 166 */ "limit_opt ::=",
+ /* 167 */ "limit_opt ::= LIMIT expr",
+ /* 168 */ "limit_opt ::= LIMIT expr OFFSET expr",
+ /* 169 */ "limit_opt ::= LIMIT expr COMMA expr",
+ /* 170 */ "cmd ::= with DELETE FROM fullname indexed_opt where_opt",
+ /* 171 */ "where_opt ::=",
+ /* 172 */ "where_opt ::= WHERE expr",
+ /* 173 */ "cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt",
+ /* 174 */ "setlist ::= setlist COMMA nm EQ expr",
+ /* 175 */ "setlist ::= nm EQ expr",
+ /* 176 */ "cmd ::= with insert_cmd INTO fullname idlist_opt select",
+ /* 177 */ "cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES",
+ /* 178 */ "insert_cmd ::= INSERT orconf",
+ /* 179 */ "insert_cmd ::= REPLACE",
+ /* 180 */ "idlist_opt ::=",
+ /* 181 */ "idlist_opt ::= LP idlist RP",
+ /* 182 */ "idlist ::= idlist COMMA nm",
+ /* 183 */ "idlist ::= nm",
+ /* 184 */ "expr ::= term",
+ /* 185 */ "expr ::= LP expr RP",
+ /* 186 */ "term ::= NULL",
+ /* 187 */ "expr ::= ID|INDEXED",
+ /* 188 */ "expr ::= JOIN_KW",
+ /* 189 */ "expr ::= nm DOT nm",
+ /* 190 */ "expr ::= nm DOT nm DOT nm",
+ /* 191 */ "term ::= INTEGER|FLOAT|BLOB",
+ /* 192 */ "term ::= STRING",
+ /* 193 */ "expr ::= VARIABLE",
+ /* 194 */ "expr ::= expr COLLATE ID|STRING",
+ /* 195 */ "expr ::= CAST LP expr AS typetoken RP",
+ /* 196 */ "expr ::= ID|INDEXED LP distinct exprlist RP",
+ /* 197 */ "expr ::= ID|INDEXED LP STAR RP",
+ /* 198 */ "term ::= CTIME_KW",
+ /* 199 */ "expr ::= expr AND expr",
+ /* 200 */ "expr ::= expr OR expr",
+ /* 201 */ "expr ::= expr LT|GT|GE|LE expr",
+ /* 202 */ "expr ::= expr EQ|NE expr",
+ /* 203 */ "expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr",
+ /* 204 */ "expr ::= expr PLUS|MINUS expr",
+ /* 205 */ "expr ::= expr STAR|SLASH|REM expr",
+ /* 206 */ "expr ::= expr CONCAT expr",
+ /* 207 */ "likeop ::= LIKE_KW|MATCH",
+ /* 208 */ "likeop ::= NOT LIKE_KW|MATCH",
+ /* 209 */ "expr ::= expr likeop expr",
+ /* 210 */ "expr ::= expr likeop expr ESCAPE expr",
+ /* 211 */ "expr ::= expr ISNULL|NOTNULL",
+ /* 212 */ "expr ::= expr NOT NULL",
+ /* 213 */ "expr ::= expr IS expr",
+ /* 214 */ "expr ::= expr IS NOT expr",
+ /* 215 */ "expr ::= NOT expr",
+ /* 216 */ "expr ::= BITNOT expr",
+ /* 217 */ "expr ::= MINUS expr",
+ /* 218 */ "expr ::= PLUS expr",
+ /* 219 */ "between_op ::= BETWEEN",
+ /* 220 */ "between_op ::= NOT BETWEEN",
+ /* 221 */ "expr ::= expr between_op expr AND expr",
+ /* 222 */ "in_op ::= IN",
+ /* 223 */ "in_op ::= NOT IN",
+ /* 224 */ "expr ::= expr in_op LP exprlist RP",
+ /* 225 */ "expr ::= LP select RP",
+ /* 226 */ "expr ::= expr in_op LP select RP",
+ /* 227 */ "expr ::= expr in_op nm dbnm",
+ /* 228 */ "expr ::= EXISTS LP select RP",
+ /* 229 */ "expr ::= CASE case_operand case_exprlist case_else END",
+ /* 230 */ "case_exprlist ::= case_exprlist WHEN expr THEN expr",
+ /* 231 */ "case_exprlist ::= WHEN expr THEN expr",
+ /* 232 */ "case_else ::= ELSE expr",
+ /* 233 */ "case_else ::=",
+ /* 234 */ "case_operand ::= expr",
+ /* 235 */ "case_operand ::=",
+ /* 236 */ "exprlist ::= nexprlist",
+ /* 237 */ "exprlist ::=",
+ /* 238 */ "nexprlist ::= nexprlist COMMA expr",
+ /* 239 */ "nexprlist ::= expr",
+ /* 240 */ "cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt",
+ /* 241 */ "uniqueflag ::= UNIQUE",
+ /* 242 */ "uniqueflag ::=",
+ /* 243 */ "eidlist_opt ::=",
+ /* 244 */ "eidlist_opt ::= LP eidlist RP",
+ /* 245 */ "eidlist ::= eidlist COMMA nm collate sortorder",
+ /* 246 */ "eidlist ::= nm collate sortorder",
+ /* 247 */ "collate ::=",
+ /* 248 */ "collate ::= COLLATE ID|STRING",
+ /* 249 */ "cmd ::= DROP INDEX ifexists fullname",
+ /* 250 */ "cmd ::= VACUUM",
+ /* 251 */ "cmd ::= VACUUM nm",
+ /* 252 */ "cmd ::= PRAGMA nm dbnm",
+ /* 253 */ "cmd ::= PRAGMA nm dbnm EQ nmnum",
+ /* 254 */ "cmd ::= PRAGMA nm dbnm LP nmnum RP",
+ /* 255 */ "cmd ::= PRAGMA nm dbnm EQ minus_num",
+ /* 256 */ "cmd ::= PRAGMA nm dbnm LP minus_num RP",
+ /* 257 */ "nmnum ::= plus_num",
+ /* 258 */ "nmnum ::= nm",
+ /* 259 */ "nmnum ::= ON",
+ /* 260 */ "nmnum ::= DELETE",
+ /* 261 */ "nmnum ::= DEFAULT",
+ /* 262 */ "plus_num ::= PLUS INTEGER|FLOAT",
+ /* 263 */ "plus_num ::= INTEGER|FLOAT",
+ /* 264 */ "minus_num ::= MINUS INTEGER|FLOAT",
+ /* 265 */ "cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END",
+ /* 266 */ "trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause",
+ /* 267 */ "trigger_time ::= BEFORE",
+ /* 268 */ "trigger_time ::= AFTER",
+ /* 269 */ "trigger_time ::= INSTEAD OF",
+ /* 270 */ "trigger_time ::=",
+ /* 271 */ "trigger_event ::= DELETE|INSERT",
+ /* 272 */ "trigger_event ::= UPDATE",
+ /* 273 */ "trigger_event ::= UPDATE OF idlist",
+ /* 274 */ "foreach_clause ::=",
+ /* 275 */ "foreach_clause ::= FOR EACH ROW",
+ /* 276 */ "when_clause ::=",
+ /* 277 */ "when_clause ::= WHEN expr",
+ /* 278 */ "trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI",
+ /* 279 */ "trigger_cmd_list ::= trigger_cmd SEMI",
+ /* 280 */ "trnm ::= nm",
+ /* 281 */ "trnm ::= nm DOT nm",
+ /* 282 */ "tridxby ::=",
+ /* 283 */ "tridxby ::= INDEXED BY nm",
+ /* 284 */ "tridxby ::= NOT INDEXED",
+ /* 285 */ "trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt",
+ /* 286 */ "trigger_cmd ::= insert_cmd INTO trnm idlist_opt select",
+ /* 287 */ "trigger_cmd ::= DELETE FROM trnm tridxby where_opt",
+ /* 288 */ "trigger_cmd ::= select",
+ /* 289 */ "expr ::= RAISE LP IGNORE RP",
+ /* 290 */ "expr ::= RAISE LP raisetype COMMA nm RP",
+ /* 291 */ "raisetype ::= ROLLBACK",
+ /* 292 */ "raisetype ::= ABORT",
+ /* 293 */ "raisetype ::= FAIL",
+ /* 294 */ "cmd ::= DROP TRIGGER ifexists fullname",
+ /* 295 */ "cmd ::= ATTACH database_kw_opt expr AS expr key_opt",
+ /* 296 */ "cmd ::= DETACH database_kw_opt expr",
+ /* 297 */ "key_opt ::=",
+ /* 298 */ "key_opt ::= KEY expr",
+ /* 299 */ "database_kw_opt ::= DATABASE",
+ /* 300 */ "database_kw_opt ::=",
+ /* 301 */ "cmd ::= REINDEX",
+ /* 302 */ "cmd ::= REINDEX nm dbnm",
+ /* 303 */ "cmd ::= ANALYZE",
+ /* 304 */ "cmd ::= ANALYZE nm dbnm",
+ /* 305 */ "cmd ::= ALTER TABLE fullname RENAME TO nm",
+ /* 306 */ "cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column",
+ /* 307 */ "add_column_fullname ::= fullname",
+ /* 308 */ "kwcolumn_opt ::=",
+ /* 309 */ "kwcolumn_opt ::= COLUMNKW",
+ /* 310 */ "cmd ::= create_vtab",
+ /* 311 */ "cmd ::= create_vtab LP vtabarglist RP",
+ /* 312 */ "create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm",
+ /* 313 */ "vtabarglist ::= vtabarg",
+ /* 314 */ "vtabarglist ::= vtabarglist COMMA vtabarg",
+ /* 315 */ "vtabarg ::=",
+ /* 316 */ "vtabarg ::= vtabarg vtabargtoken",
+ /* 317 */ "vtabargtoken ::= ANY",
+ /* 318 */ "vtabargtoken ::= lp anylist RP",
+ /* 319 */ "lp ::= LP",
+ /* 320 */ "anylist ::=",
+ /* 321 */ "anylist ::= anylist LP anylist RP",
+ /* 322 */ "anylist ::= anylist ANY",
+ /* 323 */ "with ::=",
+ /* 324 */ "with ::= WITH wqlist",
+ /* 325 */ "with ::= WITH RECURSIVE wqlist",
+ /* 326 */ "wqlist ::= nm eidlist_opt AS LP select RP",
+ /* 327 */ "wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP",
+};
+#endif /* NDEBUG */
+
+
+#if YYSTACKDEPTH<=0
+/*
+** Try to increase the size of the parser stack.
+*/
+static void yyGrowStack(yyParser *p){
+  int newSize;
+  yyStackEntry *pNew;
+
+  newSize = p->yystksz*2 + 100;
+  pNew = realloc(p->yystack, newSize*sizeof(pNew[0]));
+  if( pNew ){
+    p->yystack = pNew;
+    p->yystksz = newSize;
+#ifndef NDEBUG
+    if( yyTraceFILE ){
+      fprintf(yyTraceFILE,"%sStack grows to %d entries!\n",
+              yyTracePrompt, p->yystksz);
+    }
+#endif
+  }
+}
+#endif
+
+/* Datatype of the argument to the memory allocated passed as the
+** second argument to sqlite3ParserAlloc() below.  This can be changed by
+** putting an appropriate #define in the %include section of the input
+** grammar.
+*/
+#ifndef YYMALLOCARGTYPE
+# define YYMALLOCARGTYPE size_t
+#endif
+
+/* 
+** This function allocates a new parser.
+** The only argument is a pointer to a function which works like
+** malloc.
+**
+** Inputs:
+** A pointer to the function used to allocate memory.
+**
+** Outputs:
+** A pointer to a parser.  This pointer is used in subsequent calls
+** to sqlite3Parser and sqlite3ParserFree.
+*/
+SQLITE_PRIVATE void *sqlite3ParserAlloc(void *(*mallocProc)(YYMALLOCARGTYPE)){
+  yyParser *pParser;
+  pParser = (yyParser*)(*mallocProc)( (YYMALLOCARGTYPE)sizeof(yyParser) );
+  if( pParser ){
+    pParser->yyidx = -1;
+#ifdef YYTRACKMAXSTACKDEPTH
+    pParser->yyidxMax = 0;
+#endif
+#if YYSTACKDEPTH<=0
+    pParser->yystack = NULL;
+    pParser->yystksz = 0;
+    yyGrowStack(pParser);
+#endif
+  }
+  return pParser;
+}
+
+/* The following function deletes the "minor type" or semantic value
+** associated with a symbol.  The symbol can be either a terminal
+** or nonterminal. "yymajor" is the symbol code, and "yypminor" is
+** a pointer to the value to be deleted.  The code used to do the 
+** deletions is derived from the %destructor and/or %token_destructor
+** directives of the input grammar.
+*/
+static void yy_destructor(
+  yyParser *yypParser,    /* The parser */
+  YYCODETYPE yymajor,     /* Type code for object to destroy */
+  YYMINORTYPE *yypminor   /* The object to be destroyed */
+){
+  sqlite3ParserARG_FETCH;
+  switch( yymajor ){
+    /* Here is inserted the actions which take place when a
+    ** terminal or non-terminal is destroyed.  This can happen
+    ** when the symbol is popped from the stack during a
+    ** reduce or during error processing or when a parser is 
+    ** being destroyed before it is finished parsing.
+    **
+    ** Note: during a reduce, the only symbols destroyed are those
+    ** which appear on the RHS of the rule, but which are *not* used
+    ** inside the C code.
+    */
+/********* Begin destructor definitions ***************************************/
+    case 163: /* select */
+    case 196: /* selectnowith */
+    case 197: /* oneselect */
+    case 208: /* values */
+{
+sqlite3SelectDelete(pParse->db, (yypminor->yy387));
+}
+      break;
+    case 174: /* term */
+    case 175: /* expr */
+{
+sqlite3ExprDelete(pParse->db, (yypminor->yy118).pExpr);
+}
+      break;
+    case 179: /* eidlist_opt */
+    case 188: /* sortlist */
+    case 189: /* eidlist */
+    case 201: /* selcollist */
+    case 204: /* groupby_opt */
+    case 206: /* orderby_opt */
+    case 209: /* nexprlist */
+    case 210: /* exprlist */
+    case 211: /* sclp */
+    case 220: /* setlist */
+    case 227: /* case_exprlist */
+{
+sqlite3ExprListDelete(pParse->db, (yypminor->yy322));
+}
+      break;
+    case 195: /* fullname */
+    case 202: /* from */
+    case 213: /* seltablist */
+    case 214: /* stl_prefix */
+{
+sqlite3SrcListDelete(pParse->db, (yypminor->yy259));
+}
+      break;
+    case 198: /* with */
+    case 251: /* wqlist */
+{
+sqlite3WithDelete(pParse->db, (yypminor->yy451));
+}
+      break;
+    case 203: /* where_opt */
+    case 205: /* having_opt */
+    case 217: /* on_opt */
+    case 226: /* case_operand */
+    case 228: /* case_else */
+    case 237: /* when_clause */
+    case 242: /* key_opt */
+{
+sqlite3ExprDelete(pParse->db, (yypminor->yy314));
+}
+      break;
+    case 218: /* using_opt */
+    case 219: /* idlist */
+    case 222: /* idlist_opt */
+{
+sqlite3IdListDelete(pParse->db, (yypminor->yy384));
+}
+      break;
+    case 233: /* trigger_cmd_list */
+    case 238: /* trigger_cmd */
+{
+sqlite3DeleteTriggerStep(pParse->db, (yypminor->yy203));
+}
+      break;
+    case 235: /* trigger_event */
+{
+sqlite3IdListDelete(pParse->db, (yypminor->yy90).b);
+}
+      break;
+/********* End destructor definitions *****************************************/
+    default:  break;   /* If no destructor action specified: do nothing */
+  }
+}
+
+/*
+** Pop the parser's stack once.
+**
+** If there is a destructor routine associated with the token which
+** is popped from the stack, then call it.
+*/
+static void yy_pop_parser_stack(yyParser *pParser){
+  yyStackEntry *yytos;
+  assert( pParser->yyidx>=0 );
+  yytos = &pParser->yystack[pParser->yyidx--];
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sPopping %s\n",
+      yyTracePrompt,
+      yyTokenName[yytos->major]);
+  }
+#endif
+  yy_destructor(pParser, yytos->major, &yytos->minor);
+}
+
+/* 
+** Deallocate and destroy a parser.  Destructors are called for
+** all stack elements before shutting the parser down.
+**
+** If the YYPARSEFREENEVERNULL macro exists (for example because it
+** is defined in a %include section of the input grammar) then it is
+** assumed that the input pointer is never NULL.
+*/
+SQLITE_PRIVATE void sqlite3ParserFree(
+  void *p,                    /* The parser to be deleted */
+  void (*freeProc)(void*)     /* Function used to reclaim memory */
+){
+  yyParser *pParser = (yyParser*)p;
+#ifndef YYPARSEFREENEVERNULL
+  if( pParser==0 ) return;
+#endif
+  while( pParser->yyidx>=0 ) yy_pop_parser_stack(pParser);
+#if YYSTACKDEPTH<=0
+  free(pParser->yystack);
+#endif
+  (*freeProc)((void*)pParser);
+}
+
+/*
+** Return the peak depth of the stack for a parser.
+*/
+#ifdef YYTRACKMAXSTACKDEPTH
+SQLITE_PRIVATE int sqlite3ParserStackPeak(void *p){
+  yyParser *pParser = (yyParser*)p;
+  return pParser->yyidxMax;
+}
+#endif
+
+/*
+** Find the appropriate action for a parser given the terminal
+** look-ahead token iLookAhead.
+*/
+static int yy_find_shift_action(
+  yyParser *pParser,        /* The parser */
+  YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+  int stateno = pParser->yystack[pParser->yyidx].stateno;
+ 
+  if( stateno>=YY_MIN_REDUCE ) return stateno;
+  assert( stateno <= YY_SHIFT_COUNT );
+  do{
+    i = yy_shift_ofst[stateno];
+    if( i==YY_SHIFT_USE_DFLT ) return yy_default[stateno];
+    assert( iLookAhead!=YYNOCODE );
+    i += iLookAhead;
+    if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
+      if( iLookAhead>0 ){
+#ifdef YYFALLBACK
+        YYCODETYPE iFallback;            /* Fallback token */
+        if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])
+               && (iFallback = yyFallback[iLookAhead])!=0 ){
+#ifndef NDEBUG
+          if( yyTraceFILE ){
+            fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",
+               yyTracePrompt, yyTokenName[iLookAhead], yyTokenName[iFallback]);
+          }
+#endif
+          assert( yyFallback[iFallback]==0 ); /* Fallback loop must terminate */
+          iLookAhead = iFallback;
+          continue;
+        }
+#endif
+#ifdef YYWILDCARD
+        {
+          int j = i - iLookAhead + YYWILDCARD;
+          if( 
+#if YY_SHIFT_MIN+YYWILDCARD<0
+            j>=0 &&
+#endif
+#if YY_SHIFT_MAX+YYWILDCARD>=YY_ACTTAB_COUNT
+            j<YY_ACTTAB_COUNT &&
+#endif
+            yy_lookahead[j]==YYWILDCARD
+          ){
+#ifndef NDEBUG
+            if( yyTraceFILE ){
+              fprintf(yyTraceFILE, "%sWILDCARD %s => %s\n",
+                 yyTracePrompt, yyTokenName[iLookAhead],
+                 yyTokenName[YYWILDCARD]);
+            }
+#endif /* NDEBUG */
+            return yy_action[j];
+          }
+        }
+#endif /* YYWILDCARD */
+      }
+      return yy_default[stateno];
+    }else{
+      return yy_action[i];
+    }
+  }while(1);
+}
+
+/*
+** Find the appropriate action for a parser given the non-terminal
+** look-ahead token iLookAhead.
+*/
+static int yy_find_reduce_action(
+  int stateno,              /* Current state number */
+  YYCODETYPE iLookAhead     /* The look-ahead token */
+){
+  int i;
+#ifdef YYERRORSYMBOL
+  if( stateno>YY_REDUCE_COUNT ){
+    return yy_default[stateno];
+  }
+#else
+  assert( stateno<=YY_REDUCE_COUNT );
+#endif
+  i = yy_reduce_ofst[stateno];
+  assert( i!=YY_REDUCE_USE_DFLT );
+  assert( iLookAhead!=YYNOCODE );
+  i += iLookAhead;
+#ifdef YYERRORSYMBOL
+  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
+    return yy_default[stateno];
+  }
+#else
+  assert( i>=0 && i<YY_ACTTAB_COUNT );
+  assert( yy_lookahead[i]==iLookAhead );
+#endif
+  return yy_action[i];
+}
+
+/*
+** The following routine is called if the stack overflows.
+*/
+static void yyStackOverflow(yyParser *yypParser, YYMINORTYPE *yypMinor){
+   sqlite3ParserARG_FETCH;
+   yypParser->yyidx--;
+#ifndef NDEBUG
+   if( yyTraceFILE ){
+     fprintf(yyTraceFILE,"%sStack Overflow!\n",yyTracePrompt);
+   }
+#endif
+   while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+   /* Here code is inserted which will execute if the parser
+   ** stack every overflows */
+/******** Begin %stack_overflow code ******************************************/
+
+  UNUSED_PARAMETER(yypMinor); /* Silence some compiler warnings */
+  sqlite3ErrorMsg(pParse, "parser stack overflow");
+/******** End %stack_overflow code ********************************************/
+   sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument var */
+}
+
+/*
+** Print tracing information for a SHIFT action
+*/
+#ifndef NDEBUG
+static void yyTraceShift(yyParser *yypParser, int yyNewState){
+  if( yyTraceFILE ){
+    if( yyNewState<YYNSTATE ){
+      fprintf(yyTraceFILE,"%sShift '%s', go to state %d\n",
+         yyTracePrompt,yyTokenName[yypParser->yystack[yypParser->yyidx].major],
+         yyNewState);
+    }else{
+      fprintf(yyTraceFILE,"%sShift '%s'\n",
+         yyTracePrompt,yyTokenName[yypParser->yystack[yypParser->yyidx].major]);
+    }
+  }
+}
+#else
+# define yyTraceShift(X,Y)
+#endif
+
+/*
+** Perform a shift action.
+*/
+static void yy_shift(
+  yyParser *yypParser,          /* The parser to be shifted */
+  int yyNewState,               /* The new state to shift in */
+  int yyMajor,                  /* The major token to shift in */
+  YYMINORTYPE *yypMinor         /* Pointer to the minor token to shift in */
+){
+  yyStackEntry *yytos;
+  yypParser->yyidx++;
+#ifdef YYTRACKMAXSTACKDEPTH
+  if( yypParser->yyidx>yypParser->yyidxMax ){
+    yypParser->yyidxMax = yypParser->yyidx;
+  }
+#endif
+#if YYSTACKDEPTH>0 
+  if( yypParser->yyidx>=YYSTACKDEPTH ){
+    yyStackOverflow(yypParser, yypMinor);
+    return;
+  }
+#else
+  if( yypParser->yyidx>=yypParser->yystksz ){
+    yyGrowStack(yypParser);
+    if( yypParser->yyidx>=yypParser->yystksz ){
+      yyStackOverflow(yypParser, yypMinor);
+      return;
+    }
+  }
+#endif
+  yytos = &yypParser->yystack[yypParser->yyidx];
+  yytos->stateno = (YYACTIONTYPE)yyNewState;
+  yytos->major = (YYCODETYPE)yyMajor;
+  yytos->minor = *yypMinor;
+  yyTraceShift(yypParser, yyNewState);
+}
+
+/* The following table contains information about every rule that
+** is used during the reduce.
+*/
+static const struct {
+  YYCODETYPE lhs;         /* Symbol on the left-hand side of the rule */
+  unsigned char nrhs;     /* Number of right-hand side symbols in the rule */
+} yyRuleInfo[] = {
+  { 144, 1 },
+  { 145, 2 },
+  { 145, 1 },
+  { 146, 1 },
+  { 146, 3 },
+  { 147, 0 },
+  { 147, 1 },
+  { 147, 3 },
+  { 148, 1 },
+  { 149, 3 },
+  { 151, 0 },
+  { 151, 1 },
+  { 151, 2 },
+  { 150, 0 },
+  { 150, 1 },
+  { 150, 1 },
+  { 150, 1 },
+  { 149, 2 },
+  { 149, 2 },
+  { 149, 2 },
+  { 153, 1 },
+  { 153, 0 },
+  { 149, 2 },
+  { 149, 3 },
+  { 149, 5 },
+  { 149, 2 },
+  { 154, 6 },
+  { 156, 1 },
+  { 158, 0 },
+  { 158, 3 },
+  { 157, 1 },
+  { 157, 0 },
+  { 155, 5 },
+  { 155, 2 },
+  { 162, 0 },
+  { 162, 2 },
+  { 160, 3 },
+  { 160, 1 },
+  { 164, 3 },
+  { 165, 1 },
+  { 152, 1 },
+  { 152, 1 },
+  { 152, 1 },
+  { 166, 0 },
+  { 166, 1 },
+  { 168, 1 },
+  { 168, 4 },
+  { 168, 6 },
+  { 169, 1 },
+  { 169, 2 },
+  { 170, 1 },
+  { 170, 1 },
+  { 167, 2 },
+  { 167, 0 },
+  { 173, 2 },
+  { 173, 2 },
+  { 173, 4 },
+  { 173, 3 },
+  { 173, 3 },
+  { 173, 2 },
+  { 173, 2 },
+  { 173, 3 },
+  { 173, 5 },
+  { 173, 2 },
+  { 173, 4 },
+  { 173, 4 },
+  { 173, 1 },
+  { 173, 2 },
+  { 178, 0 },
+  { 178, 1 },
+  { 180, 0 },
+  { 180, 2 },
+  { 182, 2 },
+  { 182, 3 },
+  { 182, 3 },
+  { 182, 3 },
+  { 183, 2 },
+  { 183, 2 },
+  { 183, 1 },
+  { 183, 1 },
+  { 183, 2 },
+  { 181, 3 },
+  { 181, 2 },
+  { 184, 0 },
+  { 184, 2 },
+  { 184, 2 },
+  { 161, 0 },
+  { 161, 2 },
+  { 185, 3 },
+  { 185, 1 },
+  { 186, 1 },
+  { 186, 0 },
+  { 187, 2 },
+  { 187, 7 },
+  { 187, 5 },
+  { 187, 5 },
+  { 187, 10 },
+  { 190, 0 },
+  { 190, 1 },
+  { 176, 0 },
+  { 176, 3 },
+  { 191, 0 },
+  { 191, 2 },
+  { 192, 1 },
+  { 192, 1 },
+  { 192, 1 },
+  { 149, 4 },
+  { 194, 2 },
+  { 194, 0 },
+  { 149, 9 },
+  { 149, 4 },
+  { 149, 1 },
+  { 163, 2 },
+  { 196, 1 },
+  { 196, 3 },
+  { 199, 1 },
+  { 199, 2 },
+  { 199, 1 },
+  { 197, 9 },
+  { 197, 1 },
+  { 208, 4 },
+  { 208, 5 },
+  { 200, 1 },
+  { 200, 1 },
+  { 200, 0 },
+  { 211, 2 },
+  { 211, 0 },
+  { 201, 3 },
+  { 201, 2 },
+  { 201, 4 },
+  { 212, 2 },
+  { 212, 1 },
+  { 212, 0 },
+  { 202, 0 },
+  { 202, 2 },
+  { 214, 2 },
+  { 214, 0 },
+  { 213, 7 },
+  { 213, 9 },
+  { 213, 7 },
+  { 213, 7 },
+  { 159, 0 },
+  { 159, 2 },
+  { 195, 2 },
+  { 215, 1 },
+  { 215, 2 },
+  { 215, 3 },
+  { 215, 4 },
+  { 217, 2 },
+  { 217, 0 },
+  { 216, 0 },
+  { 216, 3 },
+  { 216, 2 },
+  { 218, 4 },
+  { 218, 0 },
+  { 206, 0 },
+  { 206, 3 },
+  { 188, 4 },
+  { 188, 2 },
+  { 177, 1 },
+  { 177, 1 },
+  { 177, 0 },
+  { 204, 0 },
+  { 204, 3 },
+  { 205, 0 },
+  { 205, 2 },
+  { 207, 0 },
+  { 207, 2 },
+  { 207, 4 },
+  { 207, 4 },
+  { 149, 6 },
+  { 203, 0 },
+  { 203, 2 },
+  { 149, 8 },
+  { 220, 5 },
+  { 220, 3 },
+  { 149, 6 },
+  { 149, 7 },
+  { 221, 2 },
+  { 221, 1 },
+  { 222, 0 },
+  { 222, 3 },
+  { 219, 3 },
+  { 219, 1 },
+  { 175, 1 },
+  { 175, 3 },
+  { 174, 1 },
+  { 175, 1 },
+  { 175, 1 },
+  { 175, 3 },
+  { 175, 5 },
+  { 174, 1 },
+  { 174, 1 },
+  { 175, 1 },
+  { 175, 3 },
+  { 175, 6 },
+  { 175, 5 },
+  { 175, 4 },
+  { 174, 1 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 3 },
+  { 223, 1 },
+  { 223, 2 },
+  { 175, 3 },
+  { 175, 5 },
+  { 175, 2 },
+  { 175, 3 },
+  { 175, 3 },
+  { 175, 4 },
+  { 175, 2 },
+  { 175, 2 },
+  { 175, 2 },
+  { 175, 2 },
+  { 224, 1 },
+  { 224, 2 },
+  { 175, 5 },
+  { 225, 1 },
+  { 225, 2 },
+  { 175, 5 },
+  { 175, 3 },
+  { 175, 5 },
+  { 175, 4 },
+  { 175, 4 },
+  { 175, 5 },
+  { 227, 5 },
+  { 227, 4 },
+  { 228, 2 },
+  { 228, 0 },
+  { 226, 1 },
+  { 226, 0 },
+  { 210, 1 },
+  { 210, 0 },
+  { 209, 3 },
+  { 209, 1 },
+  { 149, 12 },
+  { 229, 1 },
+  { 229, 0 },
+  { 179, 0 },
+  { 179, 3 },
+  { 189, 5 },
+  { 189, 3 },
+  { 230, 0 },
+  { 230, 2 },
+  { 149, 4 },
+  { 149, 1 },
+  { 149, 2 },
+  { 149, 3 },
+  { 149, 5 },
+  { 149, 6 },
+  { 149, 5 },
+  { 149, 6 },
+  { 231, 1 },
+  { 231, 1 },
+  { 231, 1 },
+  { 231, 1 },
+  { 231, 1 },
+  { 171, 2 },
+  { 171, 1 },
+  { 172, 2 },
+  { 149, 5 },
+  { 232, 11 },
+  { 234, 1 },
+  { 234, 1 },
+  { 234, 2 },
+  { 234, 0 },
+  { 235, 1 },
+  { 235, 1 },
+  { 235, 3 },
+  { 236, 0 },
+  { 236, 3 },
+  { 237, 0 },
+  { 237, 2 },
+  { 233, 3 },
+  { 233, 2 },
+  { 239, 1 },
+  { 239, 3 },
+  { 240, 0 },
+  { 240, 3 },
+  { 240, 2 },
+  { 238, 7 },
+  { 238, 5 },
+  { 238, 5 },
+  { 238, 1 },
+  { 175, 4 },
+  { 175, 6 },
+  { 193, 1 },
+  { 193, 1 },
+  { 193, 1 },
+  { 149, 4 },
+  { 149, 6 },
+  { 149, 3 },
+  { 242, 0 },
+  { 242, 2 },
+  { 241, 1 },
+  { 241, 0 },
+  { 149, 1 },
+  { 149, 3 },
+  { 149, 1 },
+  { 149, 3 },
+  { 149, 6 },
+  { 149, 6 },
+  { 243, 1 },
+  { 244, 0 },
+  { 244, 1 },
+  { 149, 1 },
+  { 149, 4 },
+  { 245, 8 },
+  { 246, 1 },
+  { 246, 3 },
+  { 247, 0 },
+  { 247, 2 },
+  { 248, 1 },
+  { 248, 3 },
+  { 249, 1 },
+  { 250, 0 },
+  { 250, 4 },
+  { 250, 2 },
+  { 198, 0 },
+  { 198, 2 },
+  { 198, 3 },
+  { 251, 6 },
+  { 251, 8 },
+};
+
+static void yy_accept(yyParser*);  /* Forward Declaration */
+
+/*
+** Perform a reduce action and the shift that must immediately
+** follow the reduce.
+*/
+static void yy_reduce(
+  yyParser *yypParser,         /* The parser */
+  int yyruleno                 /* Number of the rule by which to reduce */
+){
+  int yygoto;                     /* The next state */
+  int yyact;                      /* The next action */
+  YYMINORTYPE yygotominor;        /* The LHS of the rule reduced */
+  yyStackEntry *yymsp;            /* The top of the parser's stack */
+  int yysize;                     /* Amount to pop the stack */
+  sqlite3ParserARG_FETCH;
+  yymsp = &yypParser->yystack[yypParser->yyidx];
+#ifndef NDEBUG
+  if( yyTraceFILE && yyruleno>=0 
+        && yyruleno<(int)(sizeof(yyRuleName)/sizeof(yyRuleName[0])) ){
+    yysize = yyRuleInfo[yyruleno].nrhs;
+    fprintf(yyTraceFILE, "%sReduce [%s], go to state %d.\n", yyTracePrompt,
+      yyRuleName[yyruleno], yymsp[-yysize].stateno);
+  }
+#endif /* NDEBUG */
+  yygotominor = yyzerominor;
+
+  switch( yyruleno ){
+  /* Beginning here are the reduction cases.  A typical example
+  ** follows:
+  **   case 0:
+  **  #line <lineno> <grammarfile>
+  **     { ... }           // User supplied code
+  **  #line <lineno> <thisfile>
+  **     break;
+  */
+/********** Begin reduce actions **********************************************/
+      case 5: /* explain ::= */
+{ sqlite3BeginParse(pParse, 0); }
+        break;
+      case 6: /* explain ::= EXPLAIN */
+{ sqlite3BeginParse(pParse, 1); }
+        break;
+      case 7: /* explain ::= EXPLAIN QUERY PLAN */
+{ sqlite3BeginParse(pParse, 2); }
+        break;
+      case 8: /* cmdx ::= cmd */
+{ sqlite3FinishCoding(pParse); }
+        break;
+      case 9: /* cmd ::= BEGIN transtype trans_opt */
+{sqlite3BeginTransaction(pParse, yymsp[-1].minor.yy4);}
+        break;
+      case 13: /* transtype ::= */
+{yygotominor.yy4 = TK_DEFERRED;}
+        break;
+      case 14: /* transtype ::= DEFERRED */
+      case 15: /* transtype ::= IMMEDIATE */ yytestcase(yyruleno==15);
+      case 16: /* transtype ::= EXCLUSIVE */ yytestcase(yyruleno==16);
+      case 115: /* multiselect_op ::= UNION */ yytestcase(yyruleno==115);
+      case 117: /* multiselect_op ::= EXCEPT|INTERSECT */ yytestcase(yyruleno==117);
+{yygotominor.yy4 = yymsp[0].major;}
+        break;
+      case 17: /* cmd ::= COMMIT trans_opt */
+      case 18: /* cmd ::= END trans_opt */ yytestcase(yyruleno==18);
+{sqlite3CommitTransaction(pParse);}
+        break;
+      case 19: /* cmd ::= ROLLBACK trans_opt */
+{sqlite3RollbackTransaction(pParse);}
+        break;
+      case 22: /* cmd ::= SAVEPOINT nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_BEGIN, &yymsp[0].minor.yy0);
+}
+        break;
+      case 23: /* cmd ::= RELEASE savepoint_opt nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_RELEASE, &yymsp[0].minor.yy0);
+}
+        break;
+      case 24: /* cmd ::= ROLLBACK trans_opt TO savepoint_opt nm */
+{
+  sqlite3Savepoint(pParse, SAVEPOINT_ROLLBACK, &yymsp[0].minor.yy0);
+}
+        break;
+      case 26: /* create_table ::= createkw temp TABLE ifnotexists nm dbnm */
+{
+   sqlite3StartTable(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,yymsp[-4].minor.yy4,0,0,yymsp[-2].minor.yy4);
+}
+        break;
+      case 27: /* createkw ::= CREATE */
+{
+  pParse->db->lookaside.bEnabled = 0;
+  yygotominor.yy0 = yymsp[0].minor.yy0;
+}
+        break;
+      case 28: /* ifnotexists ::= */
+      case 31: /* temp ::= */ yytestcase(yyruleno==31);
+      case 34: /* table_options ::= */ yytestcase(yyruleno==34);
+      case 68: /* autoinc ::= */ yytestcase(yyruleno==68);
+      case 81: /* defer_subclause ::= NOT DEFERRABLE init_deferred_pred_opt */ yytestcase(yyruleno==81);
+      case 83: /* init_deferred_pred_opt ::= */ yytestcase(yyruleno==83);
+      case 85: /* init_deferred_pred_opt ::= INITIALLY IMMEDIATE */ yytestcase(yyruleno==85);
+      case 97: /* defer_subclause_opt ::= */ yytestcase(yyruleno==97);
+      case 108: /* ifexists ::= */ yytestcase(yyruleno==108);
+      case 124: /* distinct ::= */ yytestcase(yyruleno==124);
+      case 219: /* between_op ::= BETWEEN */ yytestcase(yyruleno==219);
+      case 222: /* in_op ::= IN */ yytestcase(yyruleno==222);
+      case 247: /* collate ::= */ yytestcase(yyruleno==247);
+{yygotominor.yy4 = 0;}
+        break;
+      case 29: /* ifnotexists ::= IF NOT EXISTS */
+      case 30: /* temp ::= TEMP */ yytestcase(yyruleno==30);
+      case 69: /* autoinc ::= AUTOINCR */ yytestcase(yyruleno==69);
+      case 84: /* init_deferred_pred_opt ::= INITIALLY DEFERRED */ yytestcase(yyruleno==84);
+      case 107: /* ifexists ::= IF EXISTS */ yytestcase(yyruleno==107);
+      case 220: /* between_op ::= NOT BETWEEN */ yytestcase(yyruleno==220);
+      case 223: /* in_op ::= NOT IN */ yytestcase(yyruleno==223);
+      case 248: /* collate ::= COLLATE ID|STRING */ yytestcase(yyruleno==248);
+{yygotominor.yy4 = 1;}
+        break;
+      case 32: /* create_table_args ::= LP columnlist conslist_opt RP table_options */
+{
+  sqlite3EndTable(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,yymsp[0].minor.yy4,0);
+}
+        break;
+      case 33: /* create_table_args ::= AS select */
+{
+  sqlite3EndTable(pParse,0,0,0,yymsp[0].minor.yy387);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy387);
+}
+        break;
+      case 35: /* table_options ::= WITHOUT nm */
+{
+  if( yymsp[0].minor.yy0.n==5 && sqlite3_strnicmp(yymsp[0].minor.yy0.z,"rowid",5)==0 ){
+    yygotominor.yy4 = TF_WithoutRowid | TF_NoVisibleRowid;
+  }else{
+    yygotominor.yy4 = 0;
+    sqlite3ErrorMsg(pParse, "unknown table option: %.*s", yymsp[0].minor.yy0.n, yymsp[0].minor.yy0.z);
+  }
+}
+        break;
+      case 38: /* column ::= columnid type carglist */
+{
+  yygotominor.yy0.z = yymsp[-2].minor.yy0.z;
+  yygotominor.yy0.n = (int)(pParse->sLastToken.z-yymsp[-2].minor.yy0.z) + pParse->sLastToken.n;
+}
+        break;
+      case 39: /* columnid ::= nm */
+{
+  sqlite3AddColumn(pParse,&yymsp[0].minor.yy0);
+  yygotominor.yy0 = yymsp[0].minor.yy0;
+  pParse->constraintName.n = 0;
+}
+        break;
+      case 40: /* nm ::= ID|INDEXED */
+      case 41: /* nm ::= STRING */ yytestcase(yyruleno==41);
+      case 42: /* nm ::= JOIN_KW */ yytestcase(yyruleno==42);
+      case 45: /* typetoken ::= typename */ yytestcase(yyruleno==45);
+      case 48: /* typename ::= ID|STRING */ yytestcase(yyruleno==48);
+      case 130: /* as ::= AS nm */ yytestcase(yyruleno==130);
+      case 131: /* as ::= ID|STRING */ yytestcase(yyruleno==131);
+      case 142: /* dbnm ::= DOT nm */ yytestcase(yyruleno==142);
+      case 151: /* indexed_opt ::= INDEXED BY nm */ yytestcase(yyruleno==151);
+      case 257: /* nmnum ::= plus_num */ yytestcase(yyruleno==257);
+      case 258: /* nmnum ::= nm */ yytestcase(yyruleno==258);
+      case 259: /* nmnum ::= ON */ yytestcase(yyruleno==259);
+      case 260: /* nmnum ::= DELETE */ yytestcase(yyruleno==260);
+      case 261: /* nmnum ::= DEFAULT */ yytestcase(yyruleno==261);
+      case 262: /* plus_num ::= PLUS INTEGER|FLOAT */ yytestcase(yyruleno==262);
+      case 263: /* plus_num ::= INTEGER|FLOAT */ yytestcase(yyruleno==263);
+      case 264: /* minus_num ::= MINUS INTEGER|FLOAT */ yytestcase(yyruleno==264);
+      case 280: /* trnm ::= nm */ yytestcase(yyruleno==280);
+{yygotominor.yy0 = yymsp[0].minor.yy0;}
+        break;
+      case 44: /* type ::= typetoken */
+{sqlite3AddColumnType(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 46: /* typetoken ::= typename LP signed RP */
+{
+  yygotominor.yy0.z = yymsp[-3].minor.yy0.z;
+  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-3].minor.yy0.z);
+}
+        break;
+      case 47: /* typetoken ::= typename LP signed COMMA signed RP */
+{
+  yygotominor.yy0.z = yymsp[-5].minor.yy0.z;
+  yygotominor.yy0.n = (int)(&yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] - yymsp[-5].minor.yy0.z);
+}
+        break;
+      case 49: /* typename ::= typename ID|STRING */
+{yygotominor.yy0.z=yymsp[-1].minor.yy0.z; yygotominor.yy0.n=yymsp[0].minor.yy0.n+(int)(yymsp[0].minor.yy0.z-yymsp[-1].minor.yy0.z);}
+        break;
+      case 54: /* ccons ::= CONSTRAINT nm */
+      case 92: /* tcons ::= CONSTRAINT nm */ yytestcase(yyruleno==92);
+{pParse->constraintName = yymsp[0].minor.yy0;}
+        break;
+      case 55: /* ccons ::= DEFAULT term */
+      case 57: /* ccons ::= DEFAULT PLUS term */ yytestcase(yyruleno==57);
+{sqlite3AddDefaultValue(pParse,&yymsp[0].minor.yy118);}
+        break;
+      case 56: /* ccons ::= DEFAULT LP expr RP */
+{sqlite3AddDefaultValue(pParse,&yymsp[-1].minor.yy118);}
+        break;
+      case 58: /* ccons ::= DEFAULT MINUS term */
+{
+  ExprSpan v;
+  v.pExpr = sqlite3PExpr(pParse, TK_UMINUS, yymsp[0].minor.yy118.pExpr, 0, 0);
+  v.zStart = yymsp[-1].minor.yy0.z;
+  v.zEnd = yymsp[0].minor.yy118.zEnd;
+  sqlite3AddDefaultValue(pParse,&v);
+}
+        break;
+      case 59: /* ccons ::= DEFAULT ID|INDEXED */
+{
+  ExprSpan v;
+  spanExpr(&v, pParse, TK_STRING, &yymsp[0].minor.yy0);
+  sqlite3AddDefaultValue(pParse,&v);
+}
+        break;
+      case 61: /* ccons ::= NOT NULL onconf */
+{sqlite3AddNotNull(pParse, yymsp[0].minor.yy4);}
+        break;
+      case 62: /* ccons ::= PRIMARY KEY sortorder onconf autoinc */
+{sqlite3AddPrimaryKey(pParse,0,yymsp[-1].minor.yy4,yymsp[0].minor.yy4,yymsp[-2].minor.yy4);}
+        break;
+      case 63: /* ccons ::= UNIQUE onconf */
+{sqlite3CreateIndex(pParse,0,0,0,0,yymsp[0].minor.yy4,0,0,0,0);}
+        break;
+      case 64: /* ccons ::= CHECK LP expr RP */
+{sqlite3AddCheckConstraint(pParse,yymsp[-1].minor.yy118.pExpr);}
+        break;
+      case 65: /* ccons ::= REFERENCES nm eidlist_opt refargs */
+{sqlite3CreateForeignKey(pParse,0,&yymsp[-2].minor.yy0,yymsp[-1].minor.yy322,yymsp[0].minor.yy4);}
+        break;
+      case 66: /* ccons ::= defer_subclause */
+{sqlite3DeferForeignKey(pParse,yymsp[0].minor.yy4);}
+        break;
+      case 67: /* ccons ::= COLLATE ID|STRING */
+{sqlite3AddCollateType(pParse, &yymsp[0].minor.yy0);}
+        break;
+      case 70: /* refargs ::= */
+{ yygotominor.yy4 = OE_None*0x0101; /* EV: R-19803-45884 */}
+        break;
+      case 71: /* refargs ::= refargs refarg */
+{ yygotominor.yy4 = (yymsp[-1].minor.yy4 & ~yymsp[0].minor.yy215.mask) | yymsp[0].minor.yy215.value; }
+        break;
+      case 72: /* refarg ::= MATCH nm */
+      case 73: /* refarg ::= ON INSERT refact */ yytestcase(yyruleno==73);
+{ yygotominor.yy215.value = 0;     yygotominor.yy215.mask = 0x000000; }
+        break;
+      case 74: /* refarg ::= ON DELETE refact */
+{ yygotominor.yy215.value = yymsp[0].minor.yy4;     yygotominor.yy215.mask = 0x0000ff; }
+        break;
+      case 75: /* refarg ::= ON UPDATE refact */
+{ yygotominor.yy215.value = yymsp[0].minor.yy4<<8;  yygotominor.yy215.mask = 0x00ff00; }
+        break;
+      case 76: /* refact ::= SET NULL */
+{ yygotominor.yy4 = OE_SetNull;  /* EV: R-33326-45252 */}
+        break;
+      case 77: /* refact ::= SET DEFAULT */
+{ yygotominor.yy4 = OE_SetDflt;  /* EV: R-33326-45252 */}
+        break;
+      case 78: /* refact ::= CASCADE */
+{ yygotominor.yy4 = OE_Cascade;  /* EV: R-33326-45252 */}
+        break;
+      case 79: /* refact ::= RESTRICT */
+{ yygotominor.yy4 = OE_Restrict; /* EV: R-33326-45252 */}
+        break;
+      case 80: /* refact ::= NO ACTION */
+{ yygotominor.yy4 = OE_None;     /* EV: R-33326-45252 */}
+        break;
+      case 82: /* defer_subclause ::= DEFERRABLE init_deferred_pred_opt */
+      case 98: /* defer_subclause_opt ::= defer_subclause */ yytestcase(yyruleno==98);
+      case 100: /* onconf ::= ON CONFLICT resolvetype */ yytestcase(yyruleno==100);
+      case 102: /* orconf ::= OR resolvetype */ yytestcase(yyruleno==102);
+      case 103: /* resolvetype ::= raisetype */ yytestcase(yyruleno==103);
+      case 178: /* insert_cmd ::= INSERT orconf */ yytestcase(yyruleno==178);
+{yygotominor.yy4 = yymsp[0].minor.yy4;}
+        break;
+      case 86: /* conslist_opt ::= */
+{yygotominor.yy0.n = 0; yygotominor.yy0.z = 0;}
+        break;
+      case 87: /* conslist_opt ::= COMMA conslist */
+{yygotominor.yy0 = yymsp[-1].minor.yy0;}
+        break;
+      case 90: /* tconscomma ::= COMMA */
+{pParse->constraintName.n = 0;}
+        break;
+      case 93: /* tcons ::= PRIMARY KEY LP sortlist autoinc RP onconf */
+{sqlite3AddPrimaryKey(pParse,yymsp[-3].minor.yy322,yymsp[0].minor.yy4,yymsp[-2].minor.yy4,0);}
+        break;
+      case 94: /* tcons ::= UNIQUE LP sortlist RP onconf */
+{sqlite3CreateIndex(pParse,0,0,0,yymsp[-2].minor.yy322,yymsp[0].minor.yy4,0,0,0,0);}
+        break;
+      case 95: /* tcons ::= CHECK LP expr RP onconf */
+{sqlite3AddCheckConstraint(pParse,yymsp[-2].minor.yy118.pExpr);}
+        break;
+      case 96: /* tcons ::= FOREIGN KEY LP eidlist RP REFERENCES nm eidlist_opt refargs defer_subclause_opt */
+{
+    sqlite3CreateForeignKey(pParse, yymsp[-6].minor.yy322, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy322, yymsp[-1].minor.yy4);
+    sqlite3DeferForeignKey(pParse, yymsp[0].minor.yy4);
+}
+        break;
+      case 99: /* onconf ::= */
+      case 101: /* orconf ::= */ yytestcase(yyruleno==101);
+{yygotominor.yy4 = OE_Default;}
+        break;
+      case 104: /* resolvetype ::= IGNORE */
+{yygotominor.yy4 = OE_Ignore;}
+        break;
+      case 105: /* resolvetype ::= REPLACE */
+      case 179: /* insert_cmd ::= REPLACE */ yytestcase(yyruleno==179);
+{yygotominor.yy4 = OE_Replace;}
+        break;
+      case 106: /* cmd ::= DROP TABLE ifexists fullname */
+{
+  sqlite3DropTable(pParse, yymsp[0].minor.yy259, 0, yymsp[-1].minor.yy4);
+}
+        break;
+      case 109: /* cmd ::= createkw temp VIEW ifnotexists nm dbnm eidlist_opt AS select */
+{
+  sqlite3CreateView(pParse, &yymsp[-8].minor.yy0, &yymsp[-4].minor.yy0, &yymsp[-3].minor.yy0, yymsp[-2].minor.yy322, yymsp[0].minor.yy387, yymsp[-7].minor.yy4, yymsp[-5].minor.yy4);
+}
+        break;
+      case 110: /* cmd ::= DROP VIEW ifexists fullname */
+{
+  sqlite3DropTable(pParse, yymsp[0].minor.yy259, 1, yymsp[-1].minor.yy4);
+}
+        break;
+      case 111: /* cmd ::= select */
+{
+  SelectDest dest = {SRT_Output, 0, 0, 0, 0, 0};
+  sqlite3Select(pParse, yymsp[0].minor.yy387, &dest);
+  sqlite3SelectDelete(pParse->db, yymsp[0].minor.yy387);
+}
+        break;
+      case 112: /* select ::= with selectnowith */
+{
+  Select *p = yymsp[0].minor.yy387;
+  if( p ){
+    p->pWith = yymsp[-1].minor.yy451;
+    parserDoubleLinkSelect(pParse, p);
+  }else{
+    sqlite3WithDelete(pParse->db, yymsp[-1].minor.yy451);
+  }
+  yygotominor.yy387 = p;
+}
+        break;
+      case 113: /* selectnowith ::= oneselect */
+      case 119: /* oneselect ::= values */ yytestcase(yyruleno==119);
+{yygotominor.yy387 = yymsp[0].minor.yy387;}
+        break;
+      case 114: /* selectnowith ::= selectnowith multiselect_op oneselect */
+{
+  Select *pRhs = yymsp[0].minor.yy387;
+  Select *pLhs = yymsp[-2].minor.yy387;
+  if( pRhs && pRhs->pPrior ){
+    SrcList *pFrom;
+    Token x;
+    x.n = 0;
+    parserDoubleLinkSelect(pParse, pRhs);
+    pFrom = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&x,pRhs,0,0);
+    pRhs = sqlite3SelectNew(pParse,0,pFrom,0,0,0,0,0,0,0);
+  }
+  if( pRhs ){
+    pRhs->op = (u8)yymsp[-1].minor.yy4;
+    pRhs->pPrior = pLhs;
+    if( ALWAYS(pLhs) ) pLhs->selFlags &= ~SF_MultiValue;
+    pRhs->selFlags &= ~SF_MultiValue;
+    if( yymsp[-1].minor.yy4!=TK_ALL ) pParse->hasCompound = 1;
+  }else{
+    sqlite3SelectDelete(pParse->db, pLhs);
+  }
+  yygotominor.yy387 = pRhs;
+}
+        break;
+      case 116: /* multiselect_op ::= UNION ALL */
+{yygotominor.yy4 = TK_ALL;}
+        break;
+      case 118: /* oneselect ::= SELECT distinct selcollist from where_opt groupby_opt having_opt orderby_opt limit_opt */
+{
+  yygotominor.yy387 = sqlite3SelectNew(pParse,yymsp[-6].minor.yy322,yymsp[-5].minor.yy259,yymsp[-4].minor.yy314,yymsp[-3].minor.yy322,yymsp[-2].minor.yy314,yymsp[-1].minor.yy322,yymsp[-7].minor.yy4,yymsp[0].minor.yy292.pLimit,yymsp[0].minor.yy292.pOffset);
+#if SELECTTRACE_ENABLED
+  /* Populate the Select.zSelName[] string that is used to help with
+  ** query planner debugging, to differentiate between multiple Select
+  ** objects in a complex query.
+  **
+  ** If the SELECT keyword is immediately followed by a C-style comment
+  ** then extract the first few alphanumeric characters from within that
+  ** comment to be the zSelName value.  Otherwise, the label is #N where
+  ** is an integer that is incremented with each SELECT statement seen.
+  */
+  if( yygotominor.yy387!=0 ){
+    const char *z = yymsp[-8].minor.yy0.z+6;
+    int i;
+    sqlite3_snprintf(sizeof(yygotominor.yy387->zSelName), yygotominor.yy387->zSelName, "#%d",
+                     ++pParse->nSelect);
+    while( z[0]==' ' ) z++;
+    if( z[0]=='/' && z[1]=='*' ){
+      z += 2;
+      while( z[0]==' ' ) z++;
+      for(i=0; sqlite3Isalnum(z[i]); i++){}
+      sqlite3_snprintf(sizeof(yygotominor.yy387->zSelName), yygotominor.yy387->zSelName, "%.*s", i, z);
+    }
+  }
+#endif /* SELECTRACE_ENABLED */
+}
+        break;
+      case 120: /* values ::= VALUES LP nexprlist RP */
+{
+  yygotominor.yy387 = sqlite3SelectNew(pParse,yymsp[-1].minor.yy322,0,0,0,0,0,SF_Values,0,0);
+}
+        break;
+      case 121: /* values ::= values COMMA LP exprlist RP */
+{
+  Select *pRight, *pLeft = yymsp[-4].minor.yy387;
+  pRight = sqlite3SelectNew(pParse,yymsp[-1].minor.yy322,0,0,0,0,0,SF_Values|SF_MultiValue,0,0);
+  if( ALWAYS(pLeft) ) pLeft->selFlags &= ~SF_MultiValue;
+  if( pRight ){
+    pRight->op = TK_ALL;
+    pLeft = yymsp[-4].minor.yy387;
+    pRight->pPrior = pLeft;
+    yygotominor.yy387 = pRight;
+  }else{
+    yygotominor.yy387 = pLeft;
+  }
+}
+        break;
+      case 122: /* distinct ::= DISTINCT */
+{yygotominor.yy4 = SF_Distinct;}
+        break;
+      case 123: /* distinct ::= ALL */
+{yygotominor.yy4 = SF_All;}
+        break;
+      case 125: /* sclp ::= selcollist COMMA */
+      case 244: /* eidlist_opt ::= LP eidlist RP */ yytestcase(yyruleno==244);
+{yygotominor.yy322 = yymsp[-1].minor.yy322;}
+        break;
+      case 126: /* sclp ::= */
+      case 155: /* orderby_opt ::= */ yytestcase(yyruleno==155);
+      case 162: /* groupby_opt ::= */ yytestcase(yyruleno==162);
+      case 237: /* exprlist ::= */ yytestcase(yyruleno==237);
+      case 243: /* eidlist_opt ::= */ yytestcase(yyruleno==243);
+{yygotominor.yy322 = 0;}
+        break;
+      case 127: /* selcollist ::= sclp expr as */
+{
+   yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-2].minor.yy322, yymsp[-1].minor.yy118.pExpr);
+   if( yymsp[0].minor.yy0.n>0 ) sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[0].minor.yy0, 1);
+   sqlite3ExprListSetSpan(pParse,yygotominor.yy322,&yymsp[-1].minor.yy118);
+}
+        break;
+      case 128: /* selcollist ::= sclp STAR */
+{
+  Expr *p = sqlite3Expr(pParse->db, TK_ASTERISK, 0);
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-1].minor.yy322, p);
+}
+        break;
+      case 129: /* selcollist ::= sclp nm DOT STAR */
+{
+  Expr *pRight = sqlite3PExpr(pParse, TK_ASTERISK, 0, 0, &yymsp[0].minor.yy0);
+  Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
+  Expr *pDot = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy322, pDot);
+}
+        break;
+      case 132: /* as ::= */
+{yygotominor.yy0.n = 0;}
+        break;
+      case 133: /* from ::= */
+{yygotominor.yy259 = sqlite3DbMallocZero(pParse->db, sizeof(*yygotominor.yy259));}
+        break;
+      case 134: /* from ::= FROM seltablist */
+{
+  yygotominor.yy259 = yymsp[0].minor.yy259;
+  sqlite3SrcListShiftJoinType(yygotominor.yy259);
+}
+        break;
+      case 135: /* stl_prefix ::= seltablist joinop */
+{
+   yygotominor.yy259 = yymsp[-1].minor.yy259;
+   if( ALWAYS(yygotominor.yy259 && yygotominor.yy259->nSrc>0) ) yygotominor.yy259->a[yygotominor.yy259->nSrc-1].fg.jointype = (u8)yymsp[0].minor.yy4;
+}
+        break;
+      case 136: /* stl_prefix ::= */
+{yygotominor.yy259 = 0;}
+        break;
+      case 137: /* seltablist ::= stl_prefix nm dbnm as indexed_opt on_opt using_opt */
+{
+  yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,&yymsp[-5].minor.yy0,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,0,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+  sqlite3SrcListIndexedBy(pParse, yygotominor.yy259, &yymsp[-2].minor.yy0);
+}
+        break;
+      case 138: /* seltablist ::= stl_prefix nm dbnm LP exprlist RP as on_opt using_opt */
+{
+  yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-8].minor.yy259,&yymsp[-7].minor.yy0,&yymsp[-6].minor.yy0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+  sqlite3SrcListFuncArgs(pParse, yygotominor.yy259, yymsp[-4].minor.yy322);
+}
+        break;
+      case 139: /* seltablist ::= stl_prefix LP select RP as on_opt using_opt */
+{
+    yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,0,0,&yymsp[-2].minor.yy0,yymsp[-4].minor.yy387,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+  }
+        break;
+      case 140: /* seltablist ::= stl_prefix LP seltablist RP as on_opt using_opt */
+{
+    if( yymsp[-6].minor.yy259==0 && yymsp[-2].minor.yy0.n==0 && yymsp[-1].minor.yy314==0 && yymsp[0].minor.yy384==0 ){
+      yygotominor.yy259 = yymsp[-4].minor.yy259;
+    }else if( yymsp[-4].minor.yy259->nSrc==1 ){
+      yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,0,0,&yymsp[-2].minor.yy0,0,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+      if( yygotominor.yy259 ){
+        struct SrcList_item *pNew = &yygotominor.yy259->a[yygotominor.yy259->nSrc-1];
+        struct SrcList_item *pOld = yymsp[-4].minor.yy259->a;
+        pNew->zName = pOld->zName;
+        pNew->zDatabase = pOld->zDatabase;
+        pNew->pSelect = pOld->pSelect;
+        pOld->zName = pOld->zDatabase = 0;
+        pOld->pSelect = 0;
+      }
+      sqlite3SrcListDelete(pParse->db, yymsp[-4].minor.yy259);
+    }else{
+      Select *pSubquery;
+      sqlite3SrcListShiftJoinType(yymsp[-4].minor.yy259);
+      pSubquery = sqlite3SelectNew(pParse,0,yymsp[-4].minor.yy259,0,0,0,0,SF_NestedFrom,0,0);
+      yygotominor.yy259 = sqlite3SrcListAppendFromTerm(pParse,yymsp[-6].minor.yy259,0,0,&yymsp[-2].minor.yy0,pSubquery,yymsp[-1].minor.yy314,yymsp[0].minor.yy384);
+    }
+  }
+        break;
+      case 141: /* dbnm ::= */
+      case 150: /* indexed_opt ::= */ yytestcase(yyruleno==150);
+{yygotominor.yy0.z=0; yygotominor.yy0.n=0;}
+        break;
+      case 143: /* fullname ::= nm dbnm */
+{yygotominor.yy259 = sqlite3SrcListAppend(pParse->db,0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);}
+        break;
+      case 144: /* joinop ::= COMMA|JOIN */
+{ yygotominor.yy4 = JT_INNER; }
+        break;
+      case 145: /* joinop ::= JOIN_KW JOIN */
+{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-1].minor.yy0,0,0); }
+        break;
+      case 146: /* joinop ::= JOIN_KW nm JOIN */
+{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0,0); }
+        break;
+      case 147: /* joinop ::= JOIN_KW nm nm JOIN */
+{ yygotominor.yy4 = sqlite3JoinType(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[-1].minor.yy0); }
+        break;
+      case 148: /* on_opt ::= ON expr */
+      case 165: /* having_opt ::= HAVING expr */ yytestcase(yyruleno==165);
+      case 172: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==172);
+      case 232: /* case_else ::= ELSE expr */ yytestcase(yyruleno==232);
+      case 234: /* case_operand ::= expr */ yytestcase(yyruleno==234);
+{yygotominor.yy314 = yymsp[0].minor.yy118.pExpr;}
+        break;
+      case 149: /* on_opt ::= */
+      case 164: /* having_opt ::= */ yytestcase(yyruleno==164);
+      case 171: /* where_opt ::= */ yytestcase(yyruleno==171);
+      case 233: /* case_else ::= */ yytestcase(yyruleno==233);
+      case 235: /* case_operand ::= */ yytestcase(yyruleno==235);
+{yygotominor.yy314 = 0;}
+        break;
+      case 152: /* indexed_opt ::= NOT INDEXED */
+{yygotominor.yy0.z=0; yygotominor.yy0.n=1;}
+        break;
+      case 153: /* using_opt ::= USING LP idlist RP */
+      case 181: /* idlist_opt ::= LP idlist RP */ yytestcase(yyruleno==181);
+{yygotominor.yy384 = yymsp[-1].minor.yy384;}
+        break;
+      case 154: /* using_opt ::= */
+      case 180: /* idlist_opt ::= */ yytestcase(yyruleno==180);
+{yygotominor.yy384 = 0;}
+        break;
+      case 156: /* orderby_opt ::= ORDER BY sortlist */
+      case 163: /* groupby_opt ::= GROUP BY nexprlist */ yytestcase(yyruleno==163);
+      case 236: /* exprlist ::= nexprlist */ yytestcase(yyruleno==236);
+{yygotominor.yy322 = yymsp[0].minor.yy322;}
+        break;
+      case 157: /* sortlist ::= sortlist COMMA expr sortorder */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-3].minor.yy322,yymsp[-1].minor.yy118.pExpr);
+  sqlite3ExprListSetSortOrder(yygotominor.yy322,yymsp[0].minor.yy4);
+}
+        break;
+      case 158: /* sortlist ::= expr sortorder */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,0,yymsp[-1].minor.yy118.pExpr);
+  sqlite3ExprListSetSortOrder(yygotominor.yy322,yymsp[0].minor.yy4);
+}
+        break;
+      case 159: /* sortorder ::= ASC */
+{yygotominor.yy4 = SQLITE_SO_ASC;}
+        break;
+      case 160: /* sortorder ::= DESC */
+{yygotominor.yy4 = SQLITE_SO_DESC;}
+        break;
+      case 161: /* sortorder ::= */
+{yygotominor.yy4 = SQLITE_SO_UNDEFINED;}
+        break;
+      case 166: /* limit_opt ::= */
+{yygotominor.yy292.pLimit = 0; yygotominor.yy292.pOffset = 0;}
+        break;
+      case 167: /* limit_opt ::= LIMIT expr */
+{yygotominor.yy292.pLimit = yymsp[0].minor.yy118.pExpr; yygotominor.yy292.pOffset = 0;}
+        break;
+      case 168: /* limit_opt ::= LIMIT expr OFFSET expr */
+{yygotominor.yy292.pLimit = yymsp[-2].minor.yy118.pExpr; yygotominor.yy292.pOffset = yymsp[0].minor.yy118.pExpr;}
+        break;
+      case 169: /* limit_opt ::= LIMIT expr COMMA expr */
+{yygotominor.yy292.pOffset = yymsp[-2].minor.yy118.pExpr; yygotominor.yy292.pLimit = yymsp[0].minor.yy118.pExpr;}
+        break;
+      case 170: /* cmd ::= with DELETE FROM fullname indexed_opt where_opt */
+{
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy451, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-2].minor.yy259, &yymsp[-1].minor.yy0);
+  sqlite3DeleteFrom(pParse,yymsp[-2].minor.yy259,yymsp[0].minor.yy314);
+}
+        break;
+      case 173: /* cmd ::= with UPDATE orconf fullname indexed_opt SET setlist where_opt */
+{
+  sqlite3WithPush(pParse, yymsp[-7].minor.yy451, 1);
+  sqlite3SrcListIndexedBy(pParse, yymsp[-4].minor.yy259, &yymsp[-3].minor.yy0);
+  sqlite3ExprListCheckLength(pParse,yymsp[-1].minor.yy322,"set list"); 
+  sqlite3Update(pParse,yymsp[-4].minor.yy259,yymsp[-1].minor.yy322,yymsp[0].minor.yy314,yymsp[-5].minor.yy4);
+}
+        break;
+      case 174: /* setlist ::= setlist COMMA nm EQ expr */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse, yymsp[-4].minor.yy322, yymsp[0].minor.yy118.pExpr);
+  sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[-2].minor.yy0, 1);
+}
+        break;
+      case 175: /* setlist ::= nm EQ expr */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse, 0, yymsp[0].minor.yy118.pExpr);
+  sqlite3ExprListSetName(pParse, yygotominor.yy322, &yymsp[-2].minor.yy0, 1);
+}
+        break;
+      case 176: /* cmd ::= with insert_cmd INTO fullname idlist_opt select */
+{
+  sqlite3WithPush(pParse, yymsp[-5].minor.yy451, 1);
+  sqlite3Insert(pParse, yymsp[-2].minor.yy259, yymsp[0].minor.yy387, yymsp[-1].minor.yy384, yymsp[-4].minor.yy4);
+}
+        break;
+      case 177: /* cmd ::= with insert_cmd INTO fullname idlist_opt DEFAULT VALUES */
+{
+  sqlite3WithPush(pParse, yymsp[-6].minor.yy451, 1);
+  sqlite3Insert(pParse, yymsp[-3].minor.yy259, 0, yymsp[-2].minor.yy384, yymsp[-5].minor.yy4);
+}
+        break;
+      case 182: /* idlist ::= idlist COMMA nm */
+{yygotominor.yy384 = sqlite3IdListAppend(pParse->db,yymsp[-2].minor.yy384,&yymsp[0].minor.yy0);}
+        break;
+      case 183: /* idlist ::= nm */
+{yygotominor.yy384 = sqlite3IdListAppend(pParse->db,0,&yymsp[0].minor.yy0);}
+        break;
+      case 184: /* expr ::= term */
+{yygotominor.yy118 = yymsp[0].minor.yy118;}
+        break;
+      case 185: /* expr ::= LP expr RP */
+{yygotominor.yy118.pExpr = yymsp[-1].minor.yy118.pExpr; spanSet(&yygotominor.yy118,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);}
+        break;
+      case 186: /* term ::= NULL */
+      case 191: /* term ::= INTEGER|FLOAT|BLOB */ yytestcase(yyruleno==191);
+      case 192: /* term ::= STRING */ yytestcase(yyruleno==192);
+{spanExpr(&yygotominor.yy118, pParse, yymsp[0].major, &yymsp[0].minor.yy0);}
+        break;
+      case 187: /* expr ::= ID|INDEXED */
+      case 188: /* expr ::= JOIN_KW */ yytestcase(yyruleno==188);
+{spanExpr(&yygotominor.yy118, pParse, TK_ID, &yymsp[0].minor.yy0);}
+        break;
+      case 189: /* expr ::= nm DOT nm */
+{
+  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
+  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp2, 0);
+  spanSet(&yygotominor.yy118,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0);
+}
+        break;
+      case 190: /* expr ::= nm DOT nm DOT nm */
+{
+  Expr *temp1 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-4].minor.yy0);
+  Expr *temp2 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[-2].minor.yy0);
+  Expr *temp3 = sqlite3PExpr(pParse, TK_ID, 0, 0, &yymsp[0].minor.yy0);
+  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3, 0);
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_DOT, temp1, temp4, 0);
+  spanSet(&yygotominor.yy118,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
+}
+        break;
+      case 193: /* expr ::= VARIABLE */
+{
+  if( yymsp[0].minor.yy0.n>=2 && yymsp[0].minor.yy0.z[0]=='#' && sqlite3Isdigit(yymsp[0].minor.yy0.z[1]) ){
+    /* When doing a nested parse, one can include terms in an expression
+    ** that look like this:   #1 #2 ...  These terms refer to registers
+    ** in the virtual machine.  #N is the N-th register. */
+    if( pParse->nested==0 ){
+      sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &yymsp[0].minor.yy0);
+      yygotominor.yy118.pExpr = 0;
+    }else{
+      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, &yymsp[0].minor.yy0);
+      if( yygotominor.yy118.pExpr ) sqlite3GetInt32(&yymsp[0].minor.yy0.z[1], &yygotominor.yy118.pExpr->iTable);
+    }
+  }else{
+    spanExpr(&yygotominor.yy118, pParse, TK_VARIABLE, &yymsp[0].minor.yy0);
+    sqlite3ExprAssignVarNumber(pParse, yygotominor.yy118.pExpr);
+  }
+  spanSet(&yygotominor.yy118, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
+}
+        break;
+      case 194: /* expr ::= expr COLLATE ID|STRING */
+{
+  yygotominor.yy118.pExpr = sqlite3ExprAddCollateToken(pParse, yymsp[-2].minor.yy118.pExpr, &yymsp[0].minor.yy0, 1);
+  yygotominor.yy118.zStart = yymsp[-2].minor.yy118.zStart;
+  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+}
+        break;
+      case 195: /* expr ::= CAST LP expr AS typetoken RP */
+{
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_CAST, yymsp[-3].minor.yy118.pExpr, 0, &yymsp[-1].minor.yy0);
+  spanSet(&yygotominor.yy118,&yymsp[-5].minor.yy0,&yymsp[0].minor.yy0);
+}
+        break;
+      case 196: /* expr ::= ID|INDEXED LP distinct exprlist RP */
+{
+  if( yymsp[-1].minor.yy322 && yymsp[-1].minor.yy322->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
+    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &yymsp[-4].minor.yy0);
+  }
+  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, yymsp[-1].minor.yy322, &yymsp[-4].minor.yy0);
+  spanSet(&yygotominor.yy118,&yymsp[-4].minor.yy0,&yymsp[0].minor.yy0);
+  if( yymsp[-2].minor.yy4==SF_Distinct && yygotominor.yy118.pExpr ){
+    yygotominor.yy118.pExpr->flags |= EP_Distinct;
+  }
+}
+        break;
+      case 197: /* expr ::= ID|INDEXED LP STAR RP */
+{
+  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[-3].minor.yy0);
+  spanSet(&yygotominor.yy118,&yymsp[-3].minor.yy0,&yymsp[0].minor.yy0);
+}
+        break;
+      case 198: /* term ::= CTIME_KW */
+{
+  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, 0, &yymsp[0].minor.yy0);
+  spanSet(&yygotominor.yy118, &yymsp[0].minor.yy0, &yymsp[0].minor.yy0);
+}
+        break;
+      case 199: /* expr ::= expr AND expr */
+      case 200: /* expr ::= expr OR expr */ yytestcase(yyruleno==200);
+      case 201: /* expr ::= expr LT|GT|GE|LE expr */ yytestcase(yyruleno==201);
+      case 202: /* expr ::= expr EQ|NE expr */ yytestcase(yyruleno==202);
+      case 203: /* expr ::= expr BITAND|BITOR|LSHIFT|RSHIFT expr */ yytestcase(yyruleno==203);
+      case 204: /* expr ::= expr PLUS|MINUS expr */ yytestcase(yyruleno==204);
+      case 205: /* expr ::= expr STAR|SLASH|REM expr */ yytestcase(yyruleno==205);
+      case 206: /* expr ::= expr CONCAT expr */ yytestcase(yyruleno==206);
+{spanBinaryExpr(&yygotominor.yy118,pParse,yymsp[-1].major,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy118);}
+        break;
+      case 207: /* likeop ::= LIKE_KW|MATCH */
+{yygotominor.yy342.eOperator = yymsp[0].minor.yy0; yygotominor.yy342.bNot = 0;}
+        break;
+      case 208: /* likeop ::= NOT LIKE_KW|MATCH */
+{yygotominor.yy342.eOperator = yymsp[0].minor.yy0; yygotominor.yy342.bNot = 1;}
+        break;
+      case 209: /* expr ::= expr likeop expr */
+{
+  ExprList *pList;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[0].minor.yy118.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-2].minor.yy118.pExpr);
+  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-1].minor.yy342.eOperator);
+  exprNot(pParse, yymsp[-1].minor.yy342.bNot, &yygotominor.yy118.pExpr);
+  yygotominor.yy118.zStart = yymsp[-2].minor.yy118.zStart;
+  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
+  if( yygotominor.yy118.pExpr ) yygotominor.yy118.pExpr->flags |= EP_InfixFunc;
+}
+        break;
+      case 210: /* expr ::= expr likeop expr ESCAPE expr */
+{
+  ExprList *pList;
+  pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[-4].minor.yy118.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy118.pExpr);
+  yygotominor.yy118.pExpr = sqlite3ExprFunction(pParse, pList, &yymsp[-3].minor.yy342.eOperator);
+  exprNot(pParse, yymsp[-3].minor.yy342.bNot, &yygotominor.yy118.pExpr);
+  yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
+  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
+  if( yygotominor.yy118.pExpr ) yygotominor.yy118.pExpr->flags |= EP_InfixFunc;
+}
+        break;
+      case 211: /* expr ::= expr ISNULL|NOTNULL */
+{spanUnaryPostfix(&yygotominor.yy118,pParse,yymsp[0].major,&yymsp[-1].minor.yy118,&yymsp[0].minor.yy0);}
+        break;
+      case 212: /* expr ::= expr NOT NULL */
+{spanUnaryPostfix(&yygotominor.yy118,pParse,TK_NOTNULL,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy0);}
+        break;
+      case 213: /* expr ::= expr IS expr */
+{
+  spanBinaryExpr(&yygotominor.yy118,pParse,TK_IS,&yymsp[-2].minor.yy118,&yymsp[0].minor.yy118);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy118.pExpr, yygotominor.yy118.pExpr, TK_ISNULL);
+}
+        break;
+      case 214: /* expr ::= expr IS NOT expr */
+{
+  spanBinaryExpr(&yygotominor.yy118,pParse,TK_ISNOT,&yymsp[-3].minor.yy118,&yymsp[0].minor.yy118);
+  binaryToUnaryIfNull(pParse, yymsp[0].minor.yy118.pExpr, yygotominor.yy118.pExpr, TK_NOTNULL);
+}
+        break;
+      case 215: /* expr ::= NOT expr */
+      case 216: /* expr ::= BITNOT expr */ yytestcase(yyruleno==216);
+{spanUnaryPrefix(&yygotominor.yy118,pParse,yymsp[-1].major,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+        break;
+      case 217: /* expr ::= MINUS expr */
+{spanUnaryPrefix(&yygotominor.yy118,pParse,TK_UMINUS,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+        break;
+      case 218: /* expr ::= PLUS expr */
+{spanUnaryPrefix(&yygotominor.yy118,pParse,TK_UPLUS,&yymsp[0].minor.yy118,&yymsp[-1].minor.yy0);}
+        break;
+      case 221: /* expr ::= expr between_op expr AND expr */
+{
+  ExprList *pList = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
+  pList = sqlite3ExprListAppend(pParse,pList, yymsp[0].minor.yy118.pExpr);
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_BETWEEN, yymsp[-4].minor.yy118.pExpr, 0, 0);
+  if( yygotominor.yy118.pExpr ){
+    yygotominor.yy118.pExpr->x.pList = pList;
+  }else{
+    sqlite3ExprListDelete(pParse->db, pList);
+  } 
+  exprNot(pParse, yymsp[-3].minor.yy4, &yygotominor.yy118.pExpr);
+  yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
+  yygotominor.yy118.zEnd = yymsp[0].minor.yy118.zEnd;
+}
+        break;
+      case 224: /* expr ::= expr in_op LP exprlist RP */
+{
+    if( yymsp[-1].minor.yy322==0 ){
+      /* Expressions of the form
+      **
+      **      expr1 IN ()
+      **      expr1 NOT IN ()
+      **
+      ** simplify to constants 0 (false) and 1 (true), respectively,
+      ** regardless of the value of expr1.
+      */
+      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &sqlite3IntTokens[yymsp[-3].minor.yy4]);
+      sqlite3ExprDelete(pParse->db, yymsp[-4].minor.yy118.pExpr);
+    }else if( yymsp[-1].minor.yy322->nExpr==1 ){
+      /* Expressions of the form:
+      **
+      **      expr1 IN (?1)
+      **      expr1 NOT IN (?2)
+      **
+      ** with exactly one value on the RHS can be simplified to something
+      ** like this:
+      **
+      **      expr1 == ?1
+      **      expr1 <> ?2
+      **
+      ** But, the RHS of the == or <> is marked with the EP_Generic flag
+      ** so that it may not contribute to the computation of comparison
+      ** affinity or the collating sequence to use for comparison.  Otherwise,
+      ** the semantics would be subtly different from IN or NOT IN.
+      */
+      Expr *pRHS = yymsp[-1].minor.yy322->a[0].pExpr;
+      yymsp[-1].minor.yy322->a[0].pExpr = 0;
+      sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy322);
+      /* pRHS cannot be NULL because a malloc error would have been detected
+      ** before now and control would have never reached this point */
+      if( ALWAYS(pRHS) ){
+        pRHS->flags &= ~EP_Collate;
+        pRHS->flags |= EP_Generic;
+      }
+      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, yymsp[-3].minor.yy4 ? TK_NE : TK_EQ, yymsp[-4].minor.yy118.pExpr, pRHS, 0);
+    }else{
+      yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy118.pExpr, 0, 0);
+      if( yygotominor.yy118.pExpr ){
+        yygotominor.yy118.pExpr->x.pList = yymsp[-1].minor.yy322;
+        sqlite3ExprSetHeightAndFlags(pParse, yygotominor.yy118.pExpr);
+      }else{
+        sqlite3ExprListDelete(pParse->db, yymsp[-1].minor.yy322);
+      }
+      exprNot(pParse, yymsp[-3].minor.yy4, &yygotominor.yy118.pExpr);
+    }
+    yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
+    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 225: /* expr ::= LP select RP */
+{
+    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_SELECT, 0, 0, 0);
+    if( yygotominor.yy118.pExpr ){
+      yygotominor.yy118.pExpr->x.pSelect = yymsp[-1].minor.yy387;
+      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect|EP_Subquery);
+      sqlite3ExprSetHeightAndFlags(pParse, yygotominor.yy118.pExpr);
+    }else{
+      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
+    }
+    yygotominor.yy118.zStart = yymsp[-2].minor.yy0.z;
+    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 226: /* expr ::= expr in_op LP select RP */
+{
+    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-4].minor.yy118.pExpr, 0, 0);
+    if( yygotominor.yy118.pExpr ){
+      yygotominor.yy118.pExpr->x.pSelect = yymsp[-1].minor.yy387;
+      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect|EP_Subquery);
+      sqlite3ExprSetHeightAndFlags(pParse, yygotominor.yy118.pExpr);
+    }else{
+      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
+    }
+    exprNot(pParse, yymsp[-3].minor.yy4, &yygotominor.yy118.pExpr);
+    yygotominor.yy118.zStart = yymsp[-4].minor.yy118.zStart;
+    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 227: /* expr ::= expr in_op nm dbnm */
+{
+    SrcList *pSrc = sqlite3SrcListAppend(pParse->db, 0,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0);
+    yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_IN, yymsp[-3].minor.yy118.pExpr, 0, 0);
+    if( yygotominor.yy118.pExpr ){
+      yygotominor.yy118.pExpr->x.pSelect = sqlite3SelectNew(pParse, 0,pSrc,0,0,0,0,0,0,0);
+      ExprSetProperty(yygotominor.yy118.pExpr, EP_xIsSelect|EP_Subquery);
+      sqlite3ExprSetHeightAndFlags(pParse, yygotominor.yy118.pExpr);
+    }else{
+      sqlite3SrcListDelete(pParse->db, pSrc);
+    }
+    exprNot(pParse, yymsp[-2].minor.yy4, &yygotominor.yy118.pExpr);
+    yygotominor.yy118.zStart = yymsp[-3].minor.yy118.zStart;
+    yygotominor.yy118.zEnd = yymsp[0].minor.yy0.z ? &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n] : &yymsp[-1].minor.yy0.z[yymsp[-1].minor.yy0.n];
+  }
+        break;
+      case 228: /* expr ::= EXISTS LP select RP */
+{
+    Expr *p = yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_EXISTS, 0, 0, 0);
+    if( p ){
+      p->x.pSelect = yymsp[-1].minor.yy387;
+      ExprSetProperty(p, EP_xIsSelect|EP_Subquery);
+      sqlite3ExprSetHeightAndFlags(pParse, p);
+    }else{
+      sqlite3SelectDelete(pParse->db, yymsp[-1].minor.yy387);
+    }
+    yygotominor.yy118.zStart = yymsp[-3].minor.yy0.z;
+    yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+  }
+        break;
+      case 229: /* expr ::= CASE case_operand case_exprlist case_else END */
+{
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_CASE, yymsp[-3].minor.yy314, 0, 0);
+  if( yygotominor.yy118.pExpr ){
+    yygotominor.yy118.pExpr->x.pList = yymsp[-1].minor.yy314 ? sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy322,yymsp[-1].minor.yy314) : yymsp[-2].minor.yy322;
+    sqlite3ExprSetHeightAndFlags(pParse, yygotominor.yy118.pExpr);
+  }else{
+    sqlite3ExprListDelete(pParse->db, yymsp[-2].minor.yy322);
+    sqlite3ExprDelete(pParse->db, yymsp[-1].minor.yy314);
+  }
+  yygotominor.yy118.zStart = yymsp[-4].minor.yy0.z;
+  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+}
+        break;
+      case 230: /* case_exprlist ::= case_exprlist WHEN expr THEN expr */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-4].minor.yy322, yymsp[-2].minor.yy118.pExpr);
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yygotominor.yy322, yymsp[0].minor.yy118.pExpr);
+}
+        break;
+      case 231: /* case_exprlist ::= WHEN expr THEN expr */
+{
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,0, yymsp[-2].minor.yy118.pExpr);
+  yygotominor.yy322 = sqlite3ExprListAppend(pParse,yygotominor.yy322, yymsp[0].minor.yy118.pExpr);
+}
+        break;
+      case 238: /* nexprlist ::= nexprlist COMMA expr */
+{yygotominor.yy322 = sqlite3ExprListAppend(pParse,yymsp[-2].minor.yy322,yymsp[0].minor.yy118.pExpr);}
+        break;
+      case 239: /* nexprlist ::= expr */
+{yygotominor.yy322 = sqlite3ExprListAppend(pParse,0,yymsp[0].minor.yy118.pExpr);}
+        break;
+      case 240: /* cmd ::= createkw uniqueflag INDEX ifnotexists nm dbnm ON nm LP sortlist RP where_opt */
+{
+  sqlite3CreateIndex(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, 
+                     sqlite3SrcListAppend(pParse->db,0,&yymsp[-4].minor.yy0,0), yymsp[-2].minor.yy322, yymsp[-10].minor.yy4,
+                      &yymsp[-11].minor.yy0, yymsp[0].minor.yy314, SQLITE_SO_ASC, yymsp[-8].minor.yy4);
+}
+        break;
+      case 241: /* uniqueflag ::= UNIQUE */
+      case 292: /* raisetype ::= ABORT */ yytestcase(yyruleno==292);
+{yygotominor.yy4 = OE_Abort;}
+        break;
+      case 242: /* uniqueflag ::= */
+{yygotominor.yy4 = OE_None;}
+        break;
+      case 245: /* eidlist ::= eidlist COMMA nm collate sortorder */
+{
+  yygotominor.yy322 = parserAddExprIdListTerm(pParse, yymsp[-4].minor.yy322, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy4, yymsp[0].minor.yy4);
+}
+        break;
+      case 246: /* eidlist ::= nm collate sortorder */
+{
+  yygotominor.yy322 = parserAddExprIdListTerm(pParse, 0, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy4, yymsp[0].minor.yy4);
+}
+        break;
+      case 249: /* cmd ::= DROP INDEX ifexists fullname */
+{sqlite3DropIndex(pParse, yymsp[0].minor.yy259, yymsp[-1].minor.yy4);}
+        break;
+      case 250: /* cmd ::= VACUUM */
+      case 251: /* cmd ::= VACUUM nm */ yytestcase(yyruleno==251);
+{sqlite3Vacuum(pParse);}
+        break;
+      case 252: /* cmd ::= PRAGMA nm dbnm */
+{sqlite3Pragma(pParse,&yymsp[-1].minor.yy0,&yymsp[0].minor.yy0,0,0);}
+        break;
+      case 253: /* cmd ::= PRAGMA nm dbnm EQ nmnum */
+{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,0);}
+        break;
+      case 254: /* cmd ::= PRAGMA nm dbnm LP nmnum RP */
+{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,0);}
+        break;
+      case 255: /* cmd ::= PRAGMA nm dbnm EQ minus_num */
+{sqlite3Pragma(pParse,&yymsp[-3].minor.yy0,&yymsp[-2].minor.yy0,&yymsp[0].minor.yy0,1);}
+        break;
+      case 256: /* cmd ::= PRAGMA nm dbnm LP minus_num RP */
+{sqlite3Pragma(pParse,&yymsp[-4].minor.yy0,&yymsp[-3].minor.yy0,&yymsp[-1].minor.yy0,1);}
+        break;
+      case 265: /* cmd ::= createkw trigger_decl BEGIN trigger_cmd_list END */
+{
+  Token all;
+  all.z = yymsp[-3].minor.yy0.z;
+  all.n = (int)(yymsp[0].minor.yy0.z - yymsp[-3].minor.yy0.z) + yymsp[0].minor.yy0.n;
+  sqlite3FinishTrigger(pParse, yymsp[-1].minor.yy203, &all);
+}
+        break;
+      case 266: /* trigger_decl ::= temp TRIGGER ifnotexists nm dbnm trigger_time trigger_event ON fullname foreach_clause when_clause */
+{
+  sqlite3BeginTrigger(pParse, &yymsp[-7].minor.yy0, &yymsp[-6].minor.yy0, yymsp[-5].minor.yy4, yymsp[-4].minor.yy90.a, yymsp[-4].minor.yy90.b, yymsp[-2].minor.yy259, yymsp[0].minor.yy314, yymsp[-10].minor.yy4, yymsp[-8].minor.yy4);
+  yygotominor.yy0 = (yymsp[-6].minor.yy0.n==0?yymsp[-7].minor.yy0:yymsp[-6].minor.yy0);
+}
+        break;
+      case 267: /* trigger_time ::= BEFORE */
+      case 270: /* trigger_time ::= */ yytestcase(yyruleno==270);
+{ yygotominor.yy4 = TK_BEFORE; }
+        break;
+      case 268: /* trigger_time ::= AFTER */
+{ yygotominor.yy4 = TK_AFTER;  }
+        break;
+      case 269: /* trigger_time ::= INSTEAD OF */
+{ yygotominor.yy4 = TK_INSTEAD;}
+        break;
+      case 271: /* trigger_event ::= DELETE|INSERT */
+      case 272: /* trigger_event ::= UPDATE */ yytestcase(yyruleno==272);
+{yygotominor.yy90.a = yymsp[0].major; yygotominor.yy90.b = 0;}
+        break;
+      case 273: /* trigger_event ::= UPDATE OF idlist */
+{yygotominor.yy90.a = TK_UPDATE; yygotominor.yy90.b = yymsp[0].minor.yy384;}
+        break;
+      case 276: /* when_clause ::= */
+      case 297: /* key_opt ::= */ yytestcase(yyruleno==297);
+{ yygotominor.yy314 = 0; }
+        break;
+      case 277: /* when_clause ::= WHEN expr */
+      case 298: /* key_opt ::= KEY expr */ yytestcase(yyruleno==298);
+{ yygotominor.yy314 = yymsp[0].minor.yy118.pExpr; }
+        break;
+      case 278: /* trigger_cmd_list ::= trigger_cmd_list trigger_cmd SEMI */
+{
+  assert( yymsp[-2].minor.yy203!=0 );
+  yymsp[-2].minor.yy203->pLast->pNext = yymsp[-1].minor.yy203;
+  yymsp[-2].minor.yy203->pLast = yymsp[-1].minor.yy203;
+  yygotominor.yy203 = yymsp[-2].minor.yy203;
+}
+        break;
+      case 279: /* trigger_cmd_list ::= trigger_cmd SEMI */
+{ 
+  assert( yymsp[-1].minor.yy203!=0 );
+  yymsp[-1].minor.yy203->pLast = yymsp[-1].minor.yy203;
+  yygotominor.yy203 = yymsp[-1].minor.yy203;
+}
+        break;
+      case 281: /* trnm ::= nm DOT nm */
+{
+  yygotominor.yy0 = yymsp[0].minor.yy0;
+  sqlite3ErrorMsg(pParse, 
+        "qualified table names are not allowed on INSERT, UPDATE, and DELETE "
+        "statements within triggers");
+}
+        break;
+      case 283: /* tridxby ::= INDEXED BY nm */
+{
+  sqlite3ErrorMsg(pParse,
+        "the INDEXED BY clause is not allowed on UPDATE or DELETE statements "
+        "within triggers");
+}
+        break;
+      case 284: /* tridxby ::= NOT INDEXED */
+{
+  sqlite3ErrorMsg(pParse,
+        "the NOT INDEXED clause is not allowed on UPDATE or DELETE statements "
+        "within triggers");
+}
+        break;
+      case 285: /* trigger_cmd ::= UPDATE orconf trnm tridxby SET setlist where_opt */
+{ yygotominor.yy203 = sqlite3TriggerUpdateStep(pParse->db, &yymsp[-4].minor.yy0, yymsp[-1].minor.yy322, yymsp[0].minor.yy314, yymsp[-5].minor.yy4); }
+        break;
+      case 286: /* trigger_cmd ::= insert_cmd INTO trnm idlist_opt select */
+{yygotominor.yy203 = sqlite3TriggerInsertStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[-1].minor.yy384, yymsp[0].minor.yy387, yymsp[-4].minor.yy4);}
+        break;
+      case 287: /* trigger_cmd ::= DELETE FROM trnm tridxby where_opt */
+{yygotominor.yy203 = sqlite3TriggerDeleteStep(pParse->db, &yymsp[-2].minor.yy0, yymsp[0].minor.yy314);}
+        break;
+      case 288: /* trigger_cmd ::= select */
+{yygotominor.yy203 = sqlite3TriggerSelectStep(pParse->db, yymsp[0].minor.yy387); }
+        break;
+      case 289: /* expr ::= RAISE LP IGNORE RP */
+{
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, 0); 
+  if( yygotominor.yy118.pExpr ){
+    yygotominor.yy118.pExpr->affinity = OE_Ignore;
+  }
+  yygotominor.yy118.zStart = yymsp[-3].minor.yy0.z;
+  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+}
+        break;
+      case 290: /* expr ::= RAISE LP raisetype COMMA nm RP */
+{
+  yygotominor.yy118.pExpr = sqlite3PExpr(pParse, TK_RAISE, 0, 0, &yymsp[-1].minor.yy0); 
+  if( yygotominor.yy118.pExpr ) {
+    yygotominor.yy118.pExpr->affinity = (char)yymsp[-3].minor.yy4;
+  }
+  yygotominor.yy118.zStart = yymsp[-5].minor.yy0.z;
+  yygotominor.yy118.zEnd = &yymsp[0].minor.yy0.z[yymsp[0].minor.yy0.n];
+}
+        break;
+      case 291: /* raisetype ::= ROLLBACK */
+{yygotominor.yy4 = OE_Rollback;}
+        break;
+      case 293: /* raisetype ::= FAIL */
+{yygotominor.yy4 = OE_Fail;}
+        break;
+      case 294: /* cmd ::= DROP TRIGGER ifexists fullname */
+{
+  sqlite3DropTrigger(pParse,yymsp[0].minor.yy259,yymsp[-1].minor.yy4);
+}
+        break;
+      case 295: /* cmd ::= ATTACH database_kw_opt expr AS expr key_opt */
+{
+  sqlite3Attach(pParse, yymsp[-3].minor.yy118.pExpr, yymsp[-1].minor.yy118.pExpr, yymsp[0].minor.yy314);
+}
+        break;
+      case 296: /* cmd ::= DETACH database_kw_opt expr */
+{
+  sqlite3Detach(pParse, yymsp[0].minor.yy118.pExpr);
+}
+        break;
+      case 301: /* cmd ::= REINDEX */
+{sqlite3Reindex(pParse, 0, 0);}
+        break;
+      case 302: /* cmd ::= REINDEX nm dbnm */
+{sqlite3Reindex(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
+        break;
+      case 303: /* cmd ::= ANALYZE */
+{sqlite3Analyze(pParse, 0, 0);}
+        break;
+      case 304: /* cmd ::= ANALYZE nm dbnm */
+{sqlite3Analyze(pParse, &yymsp[-1].minor.yy0, &yymsp[0].minor.yy0);}
+        break;
+      case 305: /* cmd ::= ALTER TABLE fullname RENAME TO nm */
+{
+  sqlite3AlterRenameTable(pParse,yymsp[-3].minor.yy259,&yymsp[0].minor.yy0);
+}
+        break;
+      case 306: /* cmd ::= ALTER TABLE add_column_fullname ADD kwcolumn_opt column */
+{
+  sqlite3AlterFinishAddColumn(pParse, &yymsp[0].minor.yy0);
+}
+        break;
+      case 307: /* add_column_fullname ::= fullname */
+{
+  pParse->db->lookaside.bEnabled = 0;
+  sqlite3AlterBeginAddColumn(pParse, yymsp[0].minor.yy259);
+}
+        break;
+      case 310: /* cmd ::= create_vtab */
+{sqlite3VtabFinishParse(pParse,0);}
+        break;
+      case 311: /* cmd ::= create_vtab LP vtabarglist RP */
+{sqlite3VtabFinishParse(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 312: /* create_vtab ::= createkw VIRTUAL TABLE ifnotexists nm dbnm USING nm */
+{
+    sqlite3VtabBeginParse(pParse, &yymsp[-3].minor.yy0, &yymsp[-2].minor.yy0, &yymsp[0].minor.yy0, yymsp[-4].minor.yy4);
+}
+        break;
+      case 315: /* vtabarg ::= */
+{sqlite3VtabArgInit(pParse);}
+        break;
+      case 317: /* vtabargtoken ::= ANY */
+      case 318: /* vtabargtoken ::= lp anylist RP */ yytestcase(yyruleno==318);
+      case 319: /* lp ::= LP */ yytestcase(yyruleno==319);
+{sqlite3VtabArgExtend(pParse,&yymsp[0].minor.yy0);}
+        break;
+      case 323: /* with ::= */
+{yygotominor.yy451 = 0;}
+        break;
+      case 324: /* with ::= WITH wqlist */
+      case 325: /* with ::= WITH RECURSIVE wqlist */ yytestcase(yyruleno==325);
+{ yygotominor.yy451 = yymsp[0].minor.yy451; }
+        break;
+      case 326: /* wqlist ::= nm eidlist_opt AS LP select RP */
+{
+  yygotominor.yy451 = sqlite3WithAdd(pParse, 0, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy322, yymsp[-1].minor.yy387);
+}
+        break;
+      case 327: /* wqlist ::= wqlist COMMA nm eidlist_opt AS LP select RP */
+{
+  yygotominor.yy451 = sqlite3WithAdd(pParse, yymsp[-7].minor.yy451, &yymsp[-5].minor.yy0, yymsp[-4].minor.yy322, yymsp[-1].minor.yy387);
+}
+        break;
+      default:
+      /* (0) input ::= cmdlist */ yytestcase(yyruleno==0);
+      /* (1) cmdlist ::= cmdlist ecmd */ yytestcase(yyruleno==1);
+      /* (2) cmdlist ::= ecmd */ yytestcase(yyruleno==2);
+      /* (3) ecmd ::= SEMI */ yytestcase(yyruleno==3);
+      /* (4) ecmd ::= explain cmdx SEMI */ yytestcase(yyruleno==4);
+      /* (10) trans_opt ::= */ yytestcase(yyruleno==10);
+      /* (11) trans_opt ::= TRANSACTION */ yytestcase(yyruleno==11);
+      /* (12) trans_opt ::= TRANSACTION nm */ yytestcase(yyruleno==12);
+      /* (20) savepoint_opt ::= SAVEPOINT */ yytestcase(yyruleno==20);
+      /* (21) savepoint_opt ::= */ yytestcase(yyruleno==21);
+      /* (25) cmd ::= create_table create_table_args */ yytestcase(yyruleno==25);
+      /* (36) columnlist ::= columnlist COMMA column */ yytestcase(yyruleno==36);
+      /* (37) columnlist ::= column */ yytestcase(yyruleno==37);
+      /* (43) type ::= */ yytestcase(yyruleno==43);
+      /* (50) signed ::= plus_num */ yytestcase(yyruleno==50);
+      /* (51) signed ::= minus_num */ yytestcase(yyruleno==51);
+      /* (52) carglist ::= carglist ccons */ yytestcase(yyruleno==52);
+      /* (53) carglist ::= */ yytestcase(yyruleno==53);
+      /* (60) ccons ::= NULL onconf */ yytestcase(yyruleno==60);
+      /* (88) conslist ::= conslist tconscomma tcons */ yytestcase(yyruleno==88);
+      /* (89) conslist ::= tcons */ yytestcase(yyruleno==89);
+      /* (91) tconscomma ::= */ yytestcase(yyruleno==91);
+      /* (274) foreach_clause ::= */ yytestcase(yyruleno==274);
+      /* (275) foreach_clause ::= FOR EACH ROW */ yytestcase(yyruleno==275);
+      /* (282) tridxby ::= */ yytestcase(yyruleno==282);
+      /* (299) database_kw_opt ::= DATABASE */ yytestcase(yyruleno==299);
+      /* (300) database_kw_opt ::= */ yytestcase(yyruleno==300);
+      /* (308) kwcolumn_opt ::= */ yytestcase(yyruleno==308);
+      /* (309) kwcolumn_opt ::= COLUMNKW */ yytestcase(yyruleno==309);
+      /* (313) vtabarglist ::= vtabarg */ yytestcase(yyruleno==313);
+      /* (314) vtabarglist ::= vtabarglist COMMA vtabarg */ yytestcase(yyruleno==314);
+      /* (316) vtabarg ::= vtabarg vtabargtoken */ yytestcase(yyruleno==316);
+      /* (320) anylist ::= */ yytestcase(yyruleno==320);
+      /* (321) anylist ::= anylist LP anylist RP */ yytestcase(yyruleno==321);
+      /* (322) anylist ::= anylist ANY */ yytestcase(yyruleno==322);
+        break;
+/********** End reduce actions ************************************************/
+  };
+  assert( yyruleno>=0 && yyruleno<sizeof(yyRuleInfo)/sizeof(yyRuleInfo[0]) );
+  yygoto = yyRuleInfo[yyruleno].lhs;
+  yysize = yyRuleInfo[yyruleno].nrhs;
+  yypParser->yyidx -= yysize;
+  yyact = yy_find_reduce_action(yymsp[-yysize].stateno,(YYCODETYPE)yygoto);
+  if( yyact <= YY_MAX_SHIFTREDUCE ){
+    if( yyact>YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
+    /* If the reduce action popped at least
+    ** one element off the stack, then we can push the new element back
+    ** onto the stack here, and skip the stack overflow test in yy_shift().
+    ** That gives a significant speed improvement. */
+    if( yysize ){
+      yypParser->yyidx++;
+      yymsp -= yysize-1;
+      yymsp->stateno = (YYACTIONTYPE)yyact;
+      yymsp->major = (YYCODETYPE)yygoto;
+      yymsp->minor = yygotominor;
+      yyTraceShift(yypParser, yyact);
+    }else{
+      yy_shift(yypParser,yyact,yygoto,&yygotominor);
+    }
+  }else{
+    assert( yyact == YY_ACCEPT_ACTION );
+    yy_accept(yypParser);
+  }
+}
+
+/*
+** The following code executes when the parse fails
+*/
+#ifndef YYNOERRORRECOVERY
+static void yy_parse_failed(
+  yyParser *yypParser           /* The parser */
+){
+  sqlite3ParserARG_FETCH;
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sFail!\n",yyTracePrompt);
+  }
+#endif
+  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+  /* Here code is inserted which will be executed whenever the
+  ** parser fails */
+/************ Begin %parse_failure code ***************************************/
+/************ End %parse_failure code *****************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+#endif /* YYNOERRORRECOVERY */
+
+/*
+** The following code executes when a syntax error first occurs.
+*/
+static void yy_syntax_error(
+  yyParser *yypParser,           /* The parser */
+  int yymajor,                   /* The major type of the error token */
+  YYMINORTYPE yyminor            /* The minor type of the error token */
+){
+  sqlite3ParserARG_FETCH;
+#define TOKEN (yyminor.yy0)
+/************ Begin %syntax_error code ****************************************/
+
+  UNUSED_PARAMETER(yymajor);  /* Silence some compiler warnings */
+  assert( TOKEN.z[0] );  /* The tokenizer always gives us a token */
+  sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", &TOKEN);
+/************ End %syntax_error code ******************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/*
+** The following is executed when the parser accepts
+*/
+static void yy_accept(
+  yyParser *yypParser           /* The parser */
+){
+  sqlite3ParserARG_FETCH;
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sAccept!\n",yyTracePrompt);
+  }
+#endif
+  while( yypParser->yyidx>=0 ) yy_pop_parser_stack(yypParser);
+  /* Here code is inserted which will be executed whenever the
+  ** parser accepts */
+/*********** Begin %parse_accept code *****************************************/
+/*********** End %parse_accept code *******************************************/
+  sqlite3ParserARG_STORE; /* Suppress warning about unused %extra_argument variable */
+}
+
+/* The main parser program.
+** The first argument is a pointer to a structure obtained from
+** "sqlite3ParserAlloc" which describes the current state of the parser.
+** The second argument is the major token number.  The third is
+** the minor token.  The fourth optional argument is whatever the
+** user wants (and specified in the grammar) and is available for
+** use by the action routines.
+**
+** Inputs:
+** <ul>
+** <li> A pointer to the parser (an opaque structure.)
+** <li> The major token number.
+** <li> The minor token number.
+** <li> An option argument of a grammar-specified type.
+** </ul>
+**
+** Outputs:
+** None.
+*/
+SQLITE_PRIVATE void sqlite3Parser(
+  void *yyp,                   /* The parser */
+  int yymajor,                 /* The major token code number */
+  sqlite3ParserTOKENTYPE yyminor       /* The value for the token */
+  sqlite3ParserARG_PDECL               /* Optional %extra_argument parameter */
+){
+  YYMINORTYPE yyminorunion;
+  int yyact;            /* The parser action. */
+#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
+  int yyendofinput;     /* True if we are at the end of input */
+#endif
+#ifdef YYERRORSYMBOL
+  int yyerrorhit = 0;   /* True if yymajor has invoked an error */
+#endif
+  yyParser *yypParser;  /* The parser */
+
+  /* (re)initialize the parser, if necessary */
+  yypParser = (yyParser*)yyp;
+  if( yypParser->yyidx<0 ){
+#if YYSTACKDEPTH<=0
+    if( yypParser->yystksz <=0 ){
+      /*memset(&yyminorunion, 0, sizeof(yyminorunion));*/
+      yyminorunion = yyzerominor;
+      yyStackOverflow(yypParser, &yyminorunion);
+      return;
+    }
+#endif
+    yypParser->yyidx = 0;
+    yypParser->yyerrcnt = -1;
+    yypParser->yystack[0].stateno = 0;
+    yypParser->yystack[0].major = 0;
+#ifndef NDEBUG
+    if( yyTraceFILE ){
+      fprintf(yyTraceFILE,"%sInitialize. Empty stack. State 0\n",
+              yyTracePrompt);
+    }
+#endif
+  }
+  yyminorunion.yy0 = yyminor;
+#if !defined(YYERRORSYMBOL) && !defined(YYNOERRORRECOVERY)
+  yyendofinput = (yymajor==0);
+#endif
+  sqlite3ParserARG_STORE;
+
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    fprintf(yyTraceFILE,"%sInput '%s'\n",yyTracePrompt,yyTokenName[yymajor]);
+  }
+#endif
+
+  do{
+    yyact = yy_find_shift_action(yypParser,(YYCODETYPE)yymajor);
+    if( yyact <= YY_MAX_SHIFTREDUCE ){
+      if( yyact > YY_MAX_SHIFT ) yyact += YY_MIN_REDUCE - YY_MIN_SHIFTREDUCE;
+      yy_shift(yypParser,yyact,yymajor,&yyminorunion);
+      yypParser->yyerrcnt--;
+      yymajor = YYNOCODE;
+    }else if( yyact <= YY_MAX_REDUCE ){
+      yy_reduce(yypParser,yyact-YY_MIN_REDUCE);
+    }else{
+      assert( yyact == YY_ERROR_ACTION );
+#ifdef YYERRORSYMBOL
+      int yymx;
+#endif
+#ifndef NDEBUG
+      if( yyTraceFILE ){
+        fprintf(yyTraceFILE,"%sSyntax Error!\n",yyTracePrompt);
+      }
+#endif
+#ifdef YYERRORSYMBOL
+      /* A syntax error has occurred.
+      ** The response to an error depends upon whether or not the
+      ** grammar defines an error token "ERROR".  
+      **
+      ** This is what we do if the grammar does define ERROR:
+      **
+      **  * Call the %syntax_error function.
+      **
+      **  * Begin popping the stack until we enter a state where
+      **    it is legal to shift the error symbol, then shift
+      **    the error symbol.
+      **
+      **  * Set the error count to three.
+      **
+      **  * Begin accepting and shifting new tokens.  No new error
+      **    processing will occur until three tokens have been
+      **    shifted successfully.
+      **
+      */
+      if( yypParser->yyerrcnt<0 ){
+        yy_syntax_error(yypParser,yymajor,yyminorunion);
+      }
+      yymx = yypParser->yystack[yypParser->yyidx].major;
+      if( yymx==YYERRORSYMBOL || yyerrorhit ){
+#ifndef NDEBUG
+        if( yyTraceFILE ){
+          fprintf(yyTraceFILE,"%sDiscard input token %s\n",
+             yyTracePrompt,yyTokenName[yymajor]);
+        }
+#endif
+        yy_destructor(yypParser, (YYCODETYPE)yymajor,&yyminorunion);
+        yymajor = YYNOCODE;
+      }else{
+         while(
+          yypParser->yyidx >= 0 &&
+          yymx != YYERRORSYMBOL &&
+          (yyact = yy_find_reduce_action(
+                        yypParser->yystack[yypParser->yyidx].stateno,
+                        YYERRORSYMBOL)) >= YY_MIN_REDUCE
+        ){
+          yy_pop_parser_stack(yypParser);
+        }
+        if( yypParser->yyidx < 0 || yymajor==0 ){
+          yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+          yy_parse_failed(yypParser);
+          yymajor = YYNOCODE;
+        }else if( yymx!=YYERRORSYMBOL ){
+          YYMINORTYPE u2;
+          u2.YYERRSYMDT = 0;
+          yy_shift(yypParser,yyact,YYERRORSYMBOL,&u2);
+        }
+      }
+      yypParser->yyerrcnt = 3;
+      yyerrorhit = 1;
+#elif defined(YYNOERRORRECOVERY)
+      /* If the YYNOERRORRECOVERY macro is defined, then do not attempt to
+      ** do any kind of error recovery.  Instead, simply invoke the syntax
+      ** error routine and continue going as if nothing had happened.
+      **
+      ** Applications can set this macro (for example inside %include) if
+      ** they intend to abandon the parse upon the first syntax error seen.
+      */
+      yy_syntax_error(yypParser,yymajor,yyminorunion);
+      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+      yymajor = YYNOCODE;
+      
+#else  /* YYERRORSYMBOL is not defined */
+      /* This is what we do if the grammar does not define ERROR:
+      **
+      **  * Report an error message, and throw away the input token.
+      **
+      **  * If the input token is $, then fail the parse.
+      **
+      ** As before, subsequent error messages are suppressed until
+      ** three input tokens have been successfully shifted.
+      */
+      if( yypParser->yyerrcnt<=0 ){
+        yy_syntax_error(yypParser,yymajor,yyminorunion);
+      }
+      yypParser->yyerrcnt = 3;
+      yy_destructor(yypParser,(YYCODETYPE)yymajor,&yyminorunion);
+      if( yyendofinput ){
+        yy_parse_failed(yypParser);
+      }
+      yymajor = YYNOCODE;
+#endif
+    }
+  }while( yymajor!=YYNOCODE && yypParser->yyidx>=0 );
+#ifndef NDEBUG
+  if( yyTraceFILE ){
+    int i;
+    fprintf(yyTraceFILE,"%sReturn. Stack=",yyTracePrompt);
+    for(i=1; i<=yypParser->yyidx; i++)
+      fprintf(yyTraceFILE,"%c%s", i==1 ? '[' : ' ', 
+              yyTokenName[yypParser->yystack[i].major]);
+    fprintf(yyTraceFILE,"]\n");
+  }
+#endif
+  return;
+}
+
+/************** End of parse.c ***********************************************/
+/************** Begin file tokenize.c ****************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that splits an SQL input string up into
+** individual tokens and sends those tokens one-by-one over to the
+** parser for analysis.
+*/
+/* #include "sqliteInt.h" */
+/* #include <stdlib.h> */
+
+/*
+** The charMap() macro maps alphabetic characters into their
+** lower-case ASCII equivalent.  On ASCII machines, this is just
+** an upper-to-lower case map.  On EBCDIC machines we also need
+** to adjust the encoding.  Only alphabetic characters and underscores
+** need to be translated.
+*/
+#ifdef SQLITE_ASCII
+# define charMap(X) sqlite3UpperToLower[(unsigned char)X]
+#endif
+#ifdef SQLITE_EBCDIC
+# define charMap(X) ebcdicToAscii[(unsigned char)X]
+const unsigned char ebcdicToAscii[] = {
+/* 0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 0x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 1x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 2x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 3x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 4x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 5x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 95,  0,  0,  /* 6x */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* 7x */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* 8x */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* 9x */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ax */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Bx */
+   0, 97, 98, 99,100,101,102,103,104,105,  0,  0,  0,  0,  0,  0,  /* Cx */
+   0,106,107,108,109,110,111,112,113,114,  0,  0,  0,  0,  0,  0,  /* Dx */
+   0,  0,115,116,117,118,119,120,121,122,  0,  0,  0,  0,  0,  0,  /* Ex */
+   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  /* Fx */
+};
+#endif
+
+/*
+** The sqlite3KeywordCode function looks up an identifier to determine if
+** it is a keyword.  If it is a keyword, the token code of that keyword is 
+** returned.  If the input is not a keyword, TK_ID is returned.
+**
+** The implementation of this routine was generated by a program,
+** mkkeywordhash.h, located in the tool subdirectory of the distribution.
+** The output of the mkkeywordhash.c program is written into a file
+** named keywordhash.h and then included into this source file by
+** the #include below.
+*/
+/************** Include keywordhash.h in the middle of tokenize.c ************/
+/************** Begin file keywordhash.h *************************************/
+/***** This file contains automatically generated code ******
+**
+** The code in this file has been automatically generated by
+**
+**   sqlite/tool/mkkeywordhash.c
+**
+** The code in this file implements a function that determines whether
+** or not a given identifier is really an SQL keyword.  The same thing
+** might be implemented more directly using a hand-written hash table.
+** But by using this automatically generated code, the size of the code
+** is substantially reduced.  This is important for embedded applications
+** on platforms with limited memory.
+*/
+/* Hash score: 182 */
+static int keywordCode(const char *z, int n, int *pType){
+  /* zText[] encodes 834 bytes of keywords in 554 bytes */
+  /*   REINDEXEDESCAPEACHECKEYBEFOREIGNOREGEXPLAINSTEADDATABASELECT       */
+  /*   ABLEFTHENDEFERRABLELSEXCEPTRANSACTIONATURALTERAISEXCLUSIVE         */
+  /*   XISTSAVEPOINTERSECTRIGGEREFERENCESCONSTRAINTOFFSETEMPORARY         */
+  /*   UNIQUERYWITHOUTERELEASEATTACHAVINGROUPDATEBEGINNERECURSIVE         */
+  /*   BETWEENOTNULLIKECASCADELETECASECOLLATECREATECURRENT_DATEDETACH     */
+  /*   IMMEDIATEJOINSERTMATCHPLANALYZEPRAGMABORTVALUESVIRTUALIMITWHEN     */
+  /*   WHERENAMEAFTEREPLACEANDEFAULTAUTOINCREMENTCASTCOLUMNCOMMIT         */
+  /*   CONFLICTCROSSCURRENT_TIMESTAMPRIMARYDEFERREDISTINCTDROPFAIL        */
+  /*   FROMFULLGLOBYIFISNULLORDERESTRICTRIGHTROLLBACKROWUNIONUSING        */
+  /*   VACUUMVIEWINITIALLY                                                */
+  static const char zText[553] = {
+    'R','E','I','N','D','E','X','E','D','E','S','C','A','P','E','A','C','H',
+    'E','C','K','E','Y','B','E','F','O','R','E','I','G','N','O','R','E','G',
+    'E','X','P','L','A','I','N','S','T','E','A','D','D','A','T','A','B','A',
+    'S','E','L','E','C','T','A','B','L','E','F','T','H','E','N','D','E','F',
+    'E','R','R','A','B','L','E','L','S','E','X','C','E','P','T','R','A','N',
+    'S','A','C','T','I','O','N','A','T','U','R','A','L','T','E','R','A','I',
+    'S','E','X','C','L','U','S','I','V','E','X','I','S','T','S','A','V','E',
+    'P','O','I','N','T','E','R','S','E','C','T','R','I','G','G','E','R','E',
+    'F','E','R','E','N','C','E','S','C','O','N','S','T','R','A','I','N','T',
+    'O','F','F','S','E','T','E','M','P','O','R','A','R','Y','U','N','I','Q',
+    'U','E','R','Y','W','I','T','H','O','U','T','E','R','E','L','E','A','S',
+    'E','A','T','T','A','C','H','A','V','I','N','G','R','O','U','P','D','A',
+    'T','E','B','E','G','I','N','N','E','R','E','C','U','R','S','I','V','E',
+    'B','E','T','W','E','E','N','O','T','N','U','L','L','I','K','E','C','A',
+    'S','C','A','D','E','L','E','T','E','C','A','S','E','C','O','L','L','A',
+    'T','E','C','R','E','A','T','E','C','U','R','R','E','N','T','_','D','A',
+    'T','E','D','E','T','A','C','H','I','M','M','E','D','I','A','T','E','J',
+    'O','I','N','S','E','R','T','M','A','T','C','H','P','L','A','N','A','L',
+    'Y','Z','E','P','R','A','G','M','A','B','O','R','T','V','A','L','U','E',
+    'S','V','I','R','T','U','A','L','I','M','I','T','W','H','E','N','W','H',
+    'E','R','E','N','A','M','E','A','F','T','E','R','E','P','L','A','C','E',
+    'A','N','D','E','F','A','U','L','T','A','U','T','O','I','N','C','R','E',
+    'M','E','N','T','C','A','S','T','C','O','L','U','M','N','C','O','M','M',
+    'I','T','C','O','N','F','L','I','C','T','C','R','O','S','S','C','U','R',
+    'R','E','N','T','_','T','I','M','E','S','T','A','M','P','R','I','M','A',
+    'R','Y','D','E','F','E','R','R','E','D','I','S','T','I','N','C','T','D',
+    'R','O','P','F','A','I','L','F','R','O','M','F','U','L','L','G','L','O',
+    'B','Y','I','F','I','S','N','U','L','L','O','R','D','E','R','E','S','T',
+    'R','I','C','T','R','I','G','H','T','R','O','L','L','B','A','C','K','R',
+    'O','W','U','N','I','O','N','U','S','I','N','G','V','A','C','U','U','M',
+    'V','I','E','W','I','N','I','T','I','A','L','L','Y',
+  };
+  static const unsigned char aHash[127] = {
+      76, 105, 117,  74,   0,  45,   0,   0,  82,   0,  77,   0,   0,
+      42,  12,  78,  15,   0, 116,  85,  54, 112,   0,  19,   0,   0,
+     121,   0, 119, 115,   0,  22,  93,   0,   9,   0,   0,  70,  71,
+       0,  69,   6,   0,  48,  90, 102,   0, 118, 101,   0,   0,  44,
+       0, 103,  24,   0,  17,   0, 122,  53,  23,   0,   5, 110,  25,
+      96,   0,   0, 124, 106,  60, 123,  57,  28,  55,   0,  91,   0,
+     100,  26,   0,  99,   0,   0,   0,  95,  92,  97,  88, 109,  14,
+      39, 108,   0,  81,   0,  18,  89, 111,  32,   0, 120,  80, 113,
+      62,  46,  84,   0,   0,  94,  40,  59, 114,   0,  36,   0,   0,
+      29,   0,  86,  63,  64,   0,  20,  61,   0,  56,
+  };
+  static const unsigned char aNext[124] = {
+       0,   0,   0,   0,   4,   0,   0,   0,   0,   0,   0,   0,   0,
+       0,   2,   0,   0,   0,   0,   0,   0,  13,   0,   0,   0,   0,
+       0,   7,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+       0,   0,   0,   0,  33,   0,  21,   0,   0,   0,   0,   0,  50,
+       0,  43,   3,  47,   0,   0,   0,   0,  30,   0,  58,   0,  38,
+       0,   0,   0,   1,  66,   0,   0,  67,   0,  41,   0,   0,   0,
+       0,   0,   0,  49,  65,   0,   0,   0,   0,  31,  52,  16,  34,
+      10,   0,   0,   0,   0,   0,   0,   0,  11,  72,  79,   0,   8,
+       0, 104,  98,   0, 107,   0,  87,   0,  75,  51,   0,  27,  37,
+      73,  83,   0,  35,  68,   0,   0,
+  };
+  static const unsigned char aLen[124] = {
+       7,   7,   5,   4,   6,   4,   5,   3,   6,   7,   3,   6,   6,
+       7,   7,   3,   8,   2,   6,   5,   4,   4,   3,  10,   4,   6,
+      11,   6,   2,   7,   5,   5,   9,   6,   9,   9,   7,  10,  10,
+       4,   6,   2,   3,   9,   4,   2,   6,   5,   7,   4,   5,   7,
+       6,   6,   5,   6,   5,   5,   9,   7,   7,   3,   2,   4,   4,
+       7,   3,   6,   4,   7,   6,  12,   6,   9,   4,   6,   5,   4,
+       7,   6,   5,   6,   7,   5,   4,   5,   6,   5,   7,   3,   7,
+      13,   2,   2,   4,   6,   6,   8,   5,  17,  12,   7,   8,   8,
+       2,   4,   4,   4,   4,   4,   2,   2,   6,   5,   8,   5,   8,
+       3,   5,   5,   6,   4,   9,   3,
+  };
+  static const unsigned short int aOffset[124] = {
+       0,   2,   2,   8,   9,  14,  16,  20,  23,  25,  25,  29,  33,
+      36,  41,  46,  48,  53,  54,  59,  62,  65,  67,  69,  78,  81,
+      86,  91,  95,  96, 101, 105, 109, 117, 122, 128, 136, 142, 152,
+     159, 162, 162, 165, 167, 167, 171, 176, 179, 184, 184, 188, 192,
+     199, 204, 209, 212, 218, 221, 225, 234, 240, 240, 240, 243, 246,
+     250, 251, 255, 261, 265, 272, 278, 290, 296, 305, 307, 313, 318,
+     320, 327, 332, 337, 343, 349, 354, 358, 361, 367, 371, 378, 380,
+     387, 389, 391, 400, 404, 410, 416, 424, 429, 429, 445, 452, 459,
+     460, 467, 471, 475, 479, 483, 486, 488, 490, 496, 500, 508, 513,
+     521, 524, 529, 534, 540, 544, 549,
+  };
+  static const unsigned char aCode[124] = {
+    TK_REINDEX,    TK_INDEXED,    TK_INDEX,      TK_DESC,       TK_ESCAPE,     
+    TK_EACH,       TK_CHECK,      TK_KEY,        TK_BEFORE,     TK_FOREIGN,    
+    TK_FOR,        TK_IGNORE,     TK_LIKE_KW,    TK_EXPLAIN,    TK_INSTEAD,    
+    TK_ADD,        TK_DATABASE,   TK_AS,         TK_SELECT,     TK_TABLE,      
+    TK_JOIN_KW,    TK_THEN,       TK_END,        TK_DEFERRABLE, TK_ELSE,       
+    TK_EXCEPT,     TK_TRANSACTION,TK_ACTION,     TK_ON,         TK_JOIN_KW,    
+    TK_ALTER,      TK_RAISE,      TK_EXCLUSIVE,  TK_EXISTS,     TK_SAVEPOINT,  
+    TK_INTERSECT,  TK_TRIGGER,    TK_REFERENCES, TK_CONSTRAINT, TK_INTO,       
+    TK_OFFSET,     TK_OF,         TK_SET,        TK_TEMP,       TK_TEMP,       
+    TK_OR,         TK_UNIQUE,     TK_QUERY,      TK_WITHOUT,    TK_WITH,       
+    TK_JOIN_KW,    TK_RELEASE,    TK_ATTACH,     TK_HAVING,     TK_GROUP,      
+    TK_UPDATE,     TK_BEGIN,      TK_JOIN_KW,    TK_RECURSIVE,  TK_BETWEEN,    
+    TK_NOTNULL,    TK_NOT,        TK_NO,         TK_NULL,       TK_LIKE_KW,    
+    TK_CASCADE,    TK_ASC,        TK_DELETE,     TK_CASE,       TK_COLLATE,    
+    TK_CREATE,     TK_CTIME_KW,   TK_DETACH,     TK_IMMEDIATE,  TK_JOIN,       
+    TK_INSERT,     TK_MATCH,      TK_PLAN,       TK_ANALYZE,    TK_PRAGMA,     
+    TK_ABORT,      TK_VALUES,     TK_VIRTUAL,    TK_LIMIT,      TK_WHEN,       
+    TK_WHERE,      TK_RENAME,     TK_AFTER,      TK_REPLACE,    TK_AND,        
+    TK_DEFAULT,    TK_AUTOINCR,   TK_TO,         TK_IN,         TK_CAST,       
+    TK_COLUMNKW,   TK_COMMIT,     TK_CONFLICT,   TK_JOIN_KW,    TK_CTIME_KW,   
+    TK_CTIME_KW,   TK_PRIMARY,    TK_DEFERRED,   TK_DISTINCT,   TK_IS,         
+    TK_DROP,       TK_FAIL,       TK_FROM,       TK_JOIN_KW,    TK_LIKE_KW,    
+    TK_BY,         TK_IF,         TK_ISNULL,     TK_ORDER,      TK_RESTRICT,   
+    TK_JOIN_KW,    TK_ROLLBACK,   TK_ROW,        TK_UNION,      TK_USING,      
+    TK_VACUUM,     TK_VIEW,       TK_INITIALLY,  TK_ALL,        
+  };
+  int h, i;
+  if( n>=2 ){
+    h = ((charMap(z[0])*4) ^ (charMap(z[n-1])*3) ^ n) % 127;
+    for(i=((int)aHash[h])-1; i>=0; i=((int)aNext[i])-1){
+      if( aLen[i]==n && sqlite3StrNICmp(&zText[aOffset[i]],z,n)==0 ){
+        testcase( i==0 ); /* REINDEX */
+        testcase( i==1 ); /* INDEXED */
+        testcase( i==2 ); /* INDEX */
+        testcase( i==3 ); /* DESC */
+        testcase( i==4 ); /* ESCAPE */
+        testcase( i==5 ); /* EACH */
+        testcase( i==6 ); /* CHECK */
+        testcase( i==7 ); /* KEY */
+        testcase( i==8 ); /* BEFORE */
+        testcase( i==9 ); /* FOREIGN */
+        testcase( i==10 ); /* FOR */
+        testcase( i==11 ); /* IGNORE */
+        testcase( i==12 ); /* REGEXP */
+        testcase( i==13 ); /* EXPLAIN */
+        testcase( i==14 ); /* INSTEAD */
+        testcase( i==15 ); /* ADD */
+        testcase( i==16 ); /* DATABASE */
+        testcase( i==17 ); /* AS */
+        testcase( i==18 ); /* SELECT */
+        testcase( i==19 ); /* TABLE */
+        testcase( i==20 ); /* LEFT */
+        testcase( i==21 ); /* THEN */
+        testcase( i==22 ); /* END */
+        testcase( i==23 ); /* DEFERRABLE */
+        testcase( i==24 ); /* ELSE */
+        testcase( i==25 ); /* EXCEPT */
+        testcase( i==26 ); /* TRANSACTION */
+        testcase( i==27 ); /* ACTION */
+        testcase( i==28 ); /* ON */
+        testcase( i==29 ); /* NATURAL */
+        testcase( i==30 ); /* ALTER */
+        testcase( i==31 ); /* RAISE */
+        testcase( i==32 ); /* EXCLUSIVE */
+        testcase( i==33 ); /* EXISTS */
+        testcase( i==34 ); /* SAVEPOINT */
+        testcase( i==35 ); /* INTERSECT */
+        testcase( i==36 ); /* TRIGGER */
+        testcase( i==37 ); /* REFERENCES */
+        testcase( i==38 ); /* CONSTRAINT */
+        testcase( i==39 ); /* INTO */
+        testcase( i==40 ); /* OFFSET */
+        testcase( i==41 ); /* OF */
+        testcase( i==42 ); /* SET */
+        testcase( i==43 ); /* TEMPORARY */
+        testcase( i==44 ); /* TEMP */
+        testcase( i==45 ); /* OR */
+        testcase( i==46 ); /* UNIQUE */
+        testcase( i==47 ); /* QUERY */
+        testcase( i==48 ); /* WITHOUT */
+        testcase( i==49 ); /* WITH */
+        testcase( i==50 ); /* OUTER */
+        testcase( i==51 ); /* RELEASE */
+        testcase( i==52 ); /* ATTACH */
+        testcase( i==53 ); /* HAVING */
+        testcase( i==54 ); /* GROUP */
+        testcase( i==55 ); /* UPDATE */
+        testcase( i==56 ); /* BEGIN */
+        testcase( i==57 ); /* INNER */
+        testcase( i==58 ); /* RECURSIVE */
+        testcase( i==59 ); /* BETWEEN */
+        testcase( i==60 ); /* NOTNULL */
+        testcase( i==61 ); /* NOT */
+        testcase( i==62 ); /* NO */
+        testcase( i==63 ); /* NULL */
+        testcase( i==64 ); /* LIKE */
+        testcase( i==65 ); /* CASCADE */
+        testcase( i==66 ); /* ASC */
+        testcase( i==67 ); /* DELETE */
+        testcase( i==68 ); /* CASE */
+        testcase( i==69 ); /* COLLATE */
+        testcase( i==70 ); /* CREATE */
+        testcase( i==71 ); /* CURRENT_DATE */
+        testcase( i==72 ); /* DETACH */
+        testcase( i==73 ); /* IMMEDIATE */
+        testcase( i==74 ); /* JOIN */
+        testcase( i==75 ); /* INSERT */
+        testcase( i==76 ); /* MATCH */
+        testcase( i==77 ); /* PLAN */
+        testcase( i==78 ); /* ANALYZE */
+        testcase( i==79 ); /* PRAGMA */
+        testcase( i==80 ); /* ABORT */
+        testcase( i==81 ); /* VALUES */
+        testcase( i==82 ); /* VIRTUAL */
+        testcase( i==83 ); /* LIMIT */
+        testcase( i==84 ); /* WHEN */
+        testcase( i==85 ); /* WHERE */
+        testcase( i==86 ); /* RENAME */
+        testcase( i==87 ); /* AFTER */
+        testcase( i==88 ); /* REPLACE */
+        testcase( i==89 ); /* AND */
+        testcase( i==90 ); /* DEFAULT */
+        testcase( i==91 ); /* AUTOINCREMENT */
+        testcase( i==92 ); /* TO */
+        testcase( i==93 ); /* IN */
+        testcase( i==94 ); /* CAST */
+        testcase( i==95 ); /* COLUMN */
+        testcase( i==96 ); /* COMMIT */
+        testcase( i==97 ); /* CONFLICT */
+        testcase( i==98 ); /* CROSS */
+        testcase( i==99 ); /* CURRENT_TIMESTAMP */
+        testcase( i==100 ); /* CURRENT_TIME */
+        testcase( i==101 ); /* PRIMARY */
+        testcase( i==102 ); /* DEFERRED */
+        testcase( i==103 ); /* DISTINCT */
+        testcase( i==104 ); /* IS */
+        testcase( i==105 ); /* DROP */
+        testcase( i==106 ); /* FAIL */
+        testcase( i==107 ); /* FROM */
+        testcase( i==108 ); /* FULL */
+        testcase( i==109 ); /* GLOB */
+        testcase( i==110 ); /* BY */
+        testcase( i==111 ); /* IF */
+        testcase( i==112 ); /* ISNULL */
+        testcase( i==113 ); /* ORDER */
+        testcase( i==114 ); /* RESTRICT */
+        testcase( i==115 ); /* RIGHT */
+        testcase( i==116 ); /* ROLLBACK */
+        testcase( i==117 ); /* ROW */
+        testcase( i==118 ); /* UNION */
+        testcase( i==119 ); /* USING */
+        testcase( i==120 ); /* VACUUM */
+        testcase( i==121 ); /* VIEW */
+        testcase( i==122 ); /* INITIALLY */
+        testcase( i==123 ); /* ALL */
+        *pType = aCode[i];
+        break;
+      }
+    }
+  }
+  return n;
+}
+SQLITE_PRIVATE int sqlite3KeywordCode(const unsigned char *z, int n){
+  int id = TK_ID;
+  keywordCode((char*)z, n, &id);
+  return id;
+}
+#define SQLITE_N_KEYWORD 124
+
+/************** End of keywordhash.h *****************************************/
+/************** Continuing where we left off in tokenize.c *******************/
+
+
+/*
+** If X is a character that can be used in an identifier then
+** IdChar(X) will be true.  Otherwise it is false.
+**
+** For ASCII, any character with the high-order bit set is
+** allowed in an identifier.  For 7-bit characters, 
+** sqlite3IsIdChar[X] must be 1.
+**
+** For EBCDIC, the rules are more complex but have the same
+** end result.
+**
+** Ticket #1066.  the SQL standard does not allow '$' in the
+** middle of identifiers.  But many SQL implementations do. 
+** SQLite will allow '$' in identifiers for compatibility.
+** But the feature is undocumented.
+*/
+#ifdef SQLITE_ASCII
+#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
+#endif
+#ifdef SQLITE_EBCDIC
+SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[] = {
+/* x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 xA xB xC xD xE xF */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,  /* 4x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0,  /* 5x */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0,  /* 6x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,  /* 7x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0,  /* 8x */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0,  /* 9x */
+    1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0,  /* Ax */
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /* Bx */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Cx */
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Dx */
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1,  /* Ex */
+    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0,  /* Fx */
+};
+#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+
+/* Make the IdChar function accessible from ctime.c */
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
+SQLITE_PRIVATE int sqlite3IsIdChar(u8 c){ return IdChar(c); }
+#endif
+
+
+/*
+** Return the length of the token that begins at z[0]. 
+** Store the token type in *tokenType before returning.
+*/
+SQLITE_PRIVATE int sqlite3GetToken(const unsigned char *z, int *tokenType){
+  int i, c;
+  switch( *z ){
+    case ' ': case '\t': case '\n': case '\f': case '\r': {
+      testcase( z[0]==' ' );
+      testcase( z[0]=='\t' );
+      testcase( z[0]=='\n' );
+      testcase( z[0]=='\f' );
+      testcase( z[0]=='\r' );
+      for(i=1; sqlite3Isspace(z[i]); i++){}
+      *tokenType = TK_SPACE;
+      return i;
+    }
+    case '-': {
+      if( z[1]=='-' ){
+        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
+        *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
+        return i;
+      }
+      *tokenType = TK_MINUS;
+      return 1;
+    }
+    case '(': {
+      *tokenType = TK_LP;
+      return 1;
+    }
+    case ')': {
+      *tokenType = TK_RP;
+      return 1;
+    }
+    case ';': {
+      *tokenType = TK_SEMI;
+      return 1;
+    }
+    case '+': {
+      *tokenType = TK_PLUS;
+      return 1;
+    }
+    case '*': {
+      *tokenType = TK_STAR;
+      return 1;
+    }
+    case '/': {
+      if( z[1]!='*' || z[2]==0 ){
+        *tokenType = TK_SLASH;
+        return 1;
+      }
+      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
+      if( c ) i++;
+      *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
+      return i;
+    }
+    case '%': {
+      *tokenType = TK_REM;
+      return 1;
+    }
+    case '=': {
+      *tokenType = TK_EQ;
+      return 1 + (z[1]=='=');
+    }
+    case '<': {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_LE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_NE;
+        return 2;
+      }else if( c=='<' ){
+        *tokenType = TK_LSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_LT;
+        return 1;
+      }
+    }
+    case '>': {
+      if( (c=z[1])=='=' ){
+        *tokenType = TK_GE;
+        return 2;
+      }else if( c=='>' ){
+        *tokenType = TK_RSHIFT;
+        return 2;
+      }else{
+        *tokenType = TK_GT;
+        return 1;
+      }
+    }
+    case '!': {
+      if( z[1]!='=' ){
+        *tokenType = TK_ILLEGAL;
+        return 2;
+      }else{
+        *tokenType = TK_NE;
+        return 2;
+      }
+    }
+    case '|': {
+      if( z[1]!='|' ){
+        *tokenType = TK_BITOR;
+        return 1;
+      }else{
+        *tokenType = TK_CONCAT;
+        return 2;
+      }
+    }
+    case ',': {
+      *tokenType = TK_COMMA;
+      return 1;
+    }
+    case '&': {
+      *tokenType = TK_BITAND;
+      return 1;
+    }
+    case '~': {
+      *tokenType = TK_BITNOT;
+      return 1;
+    }
+    case '`':
+    case '\'':
+    case '"': {
+      int delim = z[0];
+      testcase( delim=='`' );
+      testcase( delim=='\'' );
+      testcase( delim=='"' );
+      for(i=1; (c=z[i])!=0; i++){
+        if( c==delim ){
+          if( z[i+1]==delim ){
+            i++;
+          }else{
+            break;
+          }
+        }
+      }
+      if( c=='\'' ){
+        *tokenType = TK_STRING;
+        return i+1;
+      }else if( c!=0 ){
+        *tokenType = TK_ID;
+        return i+1;
+      }else{
+        *tokenType = TK_ILLEGAL;
+        return i;
+      }
+    }
+    case '.': {
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( !sqlite3Isdigit(z[1]) )
+#endif
+      {
+        *tokenType = TK_DOT;
+        return 1;
+      }
+      /* If the next character is a digit, this is a floating point
+      ** number that begins with ".".  Fall thru into the next case */
+    }
+    case '0': case '1': case '2': case '3': case '4':
+    case '5': case '6': case '7': case '8': case '9': {
+      testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
+      testcase( z[0]=='3' );  testcase( z[0]=='4' );  testcase( z[0]=='5' );
+      testcase( z[0]=='6' );  testcase( z[0]=='7' );  testcase( z[0]=='8' );
+      testcase( z[0]=='9' );
+      *tokenType = TK_INTEGER;
+#ifndef SQLITE_OMIT_HEX_INTEGER
+      if( z[0]=='0' && (z[1]=='x' || z[1]=='X') && sqlite3Isxdigit(z[2]) ){
+        for(i=3; sqlite3Isxdigit(z[i]); i++){}
+        return i;
+      }
+#endif
+      for(i=0; sqlite3Isdigit(z[i]); i++){}
+#ifndef SQLITE_OMIT_FLOATING_POINT
+      if( z[i]=='.' ){
+        i++;
+        while( sqlite3Isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+      if( (z[i]=='e' || z[i]=='E') &&
+           ( sqlite3Isdigit(z[i+1]) 
+            || ((z[i+1]=='+' || z[i+1]=='-') && sqlite3Isdigit(z[i+2]))
+           )
+      ){
+        i += 2;
+        while( sqlite3Isdigit(z[i]) ){ i++; }
+        *tokenType = TK_FLOAT;
+      }
+#endif
+      while( IdChar(z[i]) ){
+        *tokenType = TK_ILLEGAL;
+        i++;
+      }
+      return i;
+    }
+    case '[': {
+      for(i=1, c=z[0]; c!=']' && (c=z[i])!=0; i++){}
+      *tokenType = c==']' ? TK_ID : TK_ILLEGAL;
+      return i;
+    }
+    case '?': {
+      *tokenType = TK_VARIABLE;
+      for(i=1; sqlite3Isdigit(z[i]); i++){}
+      return i;
+    }
+#ifndef SQLITE_OMIT_TCL_VARIABLE
+    case '$':
+#endif
+    case '@':  /* For compatibility with MS SQL Server */
+    case '#':
+    case ':': {
+      int n = 0;
+      testcase( z[0]=='$' );  testcase( z[0]=='@' );
+      testcase( z[0]==':' );  testcase( z[0]=='#' );
+      *tokenType = TK_VARIABLE;
+      for(i=1; (c=z[i])!=0; i++){
+        if( IdChar(c) ){
+          n++;
+#ifndef SQLITE_OMIT_TCL_VARIABLE
+        }else if( c=='(' && n>0 ){
+          do{
+            i++;
+          }while( (c=z[i])!=0 && !sqlite3Isspace(c) && c!=')' );
+          if( c==')' ){
+            i++;
+          }else{
+            *tokenType = TK_ILLEGAL;
+          }
+          break;
+        }else if( c==':' && z[i+1]==':' ){
+          i++;
+#endif
+        }else{
+          break;
+        }
+      }
+      if( n==0 ) *tokenType = TK_ILLEGAL;
+      return i;
+    }
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+    case 'x': case 'X': {
+      testcase( z[0]=='x' ); testcase( z[0]=='X' );
+      if( z[1]=='\'' ){
+        *tokenType = TK_BLOB;
+        for(i=2; sqlite3Isxdigit(z[i]); i++){}
+        if( z[i]!='\'' || i%2 ){
+          *tokenType = TK_ILLEGAL;
+          while( z[i] && z[i]!='\'' ){ i++; }
+        }
+        if( z[i] ) i++;
+        return i;
+      }
+      /* Otherwise fall through to the next case */
+    }
+#endif
+    default: {
+      if( !IdChar(*z) ){
+        break;
+      }
+      for(i=1; IdChar(z[i]); i++){}
+      *tokenType = TK_ID;
+      return keywordCode((char*)z, i, tokenType);
+    }
+  }
+  *tokenType = TK_ILLEGAL;
+  return 1;
+}
+
+/*
+** Run the parser on the given SQL string.  The parser structure is
+** passed in.  An SQLITE_ status code is returned.  If an error occurs
+** then an and attempt is made to write an error message into 
+** memory obtained from sqlite3_malloc() and to make *pzErrMsg point to that
+** error message.
+*/
+SQLITE_PRIVATE int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
+  int nErr = 0;                   /* Number of errors encountered */
+  int i;                          /* Loop counter */
+  void *pEngine;                  /* The LEMON-generated LALR(1) parser */
+  int tokenType;                  /* type of the next token */
+  int lastTokenParsed = -1;       /* type of the previous token */
+  u8 enableLookaside;             /* Saved value of db->lookaside.bEnabled */
+  sqlite3 *db = pParse->db;       /* The database connection */
+  int mxSqlLen;                   /* Max length of an SQL string */
+
+  assert( zSql!=0 );
+  mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
+  if( db->nVdbeActive==0 ){
+    db->u1.isInterrupted = 0;
+  }
+  pParse->rc = SQLITE_OK;
+  pParse->zTail = zSql;
+  i = 0;
+  assert( pzErrMsg!=0 );
+  /* sqlite3ParserTrace(stdout, "parser: "); */
+  pEngine = sqlite3ParserAlloc(sqlite3Malloc);
+  if( pEngine==0 ){
+    db->mallocFailed = 1;
+    return SQLITE_NOMEM;
+  }
+  assert( pParse->pNewTable==0 );
+  assert( pParse->pNewTrigger==0 );
+  assert( pParse->nVar==0 );
+  assert( pParse->nzVar==0 );
+  assert( pParse->azVar==0 );
+  enableLookaside = db->lookaside.bEnabled;
+  if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
+  while( zSql[i]!=0 ){
+    assert( i>=0 );
+    pParse->sLastToken.z = &zSql[i];
+    pParse->sLastToken.n = sqlite3GetToken((unsigned char*)&zSql[i],&tokenType);
+    i += pParse->sLastToken.n;
+    if( i>mxSqlLen ){
+      pParse->rc = SQLITE_TOOBIG;
+      break;
+    }
+    if( tokenType>=TK_SPACE ){
+      assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
+      if( db->u1.isInterrupted ){
+        sqlite3ErrorMsg(pParse, "interrupt");
+        pParse->rc = SQLITE_INTERRUPT;
+        break;
+      }
+      if( tokenType==TK_ILLEGAL ){
+        sqlite3ErrorMsg(pParse, "unrecognized token: \"%T\"",
+                        &pParse->sLastToken);
+        break;
+      }
+    }else{
+      if( tokenType==TK_SEMI ) pParse->zTail = &zSql[i];
+      sqlite3Parser(pEngine, tokenType, pParse->sLastToken, pParse);
+      lastTokenParsed = tokenType;
+      if( pParse->rc!=SQLITE_OK || db->mallocFailed ) break;
+    }
+  }
+  assert( nErr==0 );
+  if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
+    assert( zSql[i]==0 );
+    if( lastTokenParsed!=TK_SEMI ){
+      sqlite3Parser(pEngine, TK_SEMI, pParse->sLastToken, pParse);
+      pParse->zTail = &zSql[i];
+    }
+    if( pParse->rc==SQLITE_OK && db->mallocFailed==0 ){
+      sqlite3Parser(pEngine, 0, pParse->sLastToken, pParse);
+    }
+  }
+#ifdef YYTRACKMAXSTACKDEPTH
+  sqlite3_mutex_enter(sqlite3MallocMutex());
+  sqlite3StatusHighwater(SQLITE_STATUS_PARSER_STACK,
+      sqlite3ParserStackPeak(pEngine)
+  );
+  sqlite3_mutex_leave(sqlite3MallocMutex());
+#endif /* YYDEBUG */
+  sqlite3ParserFree(pEngine, sqlite3_free);
+  db->lookaside.bEnabled = enableLookaside;
+  if( db->mallocFailed ){
+    pParse->rc = SQLITE_NOMEM;
+  }
+  if( pParse->rc!=SQLITE_OK && pParse->rc!=SQLITE_DONE && pParse->zErrMsg==0 ){
+    pParse->zErrMsg = sqlite3MPrintf(db, "%s", sqlite3ErrStr(pParse->rc));
+  }
+  assert( pzErrMsg!=0 );
+  if( pParse->zErrMsg ){
+    *pzErrMsg = pParse->zErrMsg;
+    sqlite3_log(pParse->rc, "%s", *pzErrMsg);
+    pParse->zErrMsg = 0;
+    nErr++;
+  }
+  if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
+    sqlite3VdbeDelete(pParse->pVdbe);
+    pParse->pVdbe = 0;
+  }
+#ifndef SQLITE_OMIT_SHARED_CACHE
+  if( pParse->nested==0 ){
+    sqlite3DbFree(db, pParse->aTableLock);
+    pParse->aTableLock = 0;
+    pParse->nTableLock = 0;
+  }
+#endif
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3_free(pParse->apVtabLock);
+#endif
+
+  if( !IN_DECLARE_VTAB ){
+    /* If the pParse->declareVtab flag is set, do not delete any table 
+    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
+    ** will take responsibility for freeing the Table structure.
+    */
+    sqlite3DeleteTable(db, pParse->pNewTable);
+  }
+
+  sqlite3WithDelete(db, pParse->pWithToFree);
+  sqlite3DeleteTrigger(db, pParse->pNewTrigger);
+  for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
+  sqlite3DbFree(db, pParse->azVar);
+  while( pParse->pAinc ){
+    AutoincInfo *p = pParse->pAinc;
+    pParse->pAinc = p->pNext;
+    sqlite3DbFree(db, p);
+  }
+  while( pParse->pZombieTab ){
+    Table *p = pParse->pZombieTab;
+    pParse->pZombieTab = p->pNextZombie;
+    sqlite3DeleteTable(db, p);
+  }
+  assert( nErr==0 || pParse->rc!=SQLITE_OK );
+  return nErr;
+}
+
+/************** End of tokenize.c ********************************************/
+/************** Begin file complete.c ****************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** An tokenizer for SQL
+**
+** This file contains C code that implements the sqlite3_complete() API.
+** This code used to be part of the tokenizer.c source file.  But by
+** separating it out, the code will be automatically omitted from
+** static links that do not use it.
+*/
+/* #include "sqliteInt.h" */
+#ifndef SQLITE_OMIT_COMPLETE
+
+/*
+** This is defined in tokenize.c.  We just have to import the definition.
+*/
+#ifndef SQLITE_AMALGAMATION
+#ifdef SQLITE_ASCII
+#define IdChar(C)  ((sqlite3CtypeMap[(unsigned char)C]&0x46)!=0)
+#endif
+#ifdef SQLITE_EBCDIC
+SQLITE_PRIVATE const char sqlite3IsEbcdicIdChar[];
+#define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
+#endif
+#endif /* SQLITE_AMALGAMATION */
+
+
+/*
+** Token types used by the sqlite3_complete() routine.  See the header
+** comments on that procedure for additional information.
+*/
+#define tkSEMI    0
+#define tkWS      1
+#define tkOTHER   2
+#ifndef SQLITE_OMIT_TRIGGER
+#define tkEXPLAIN 3
+#define tkCREATE  4
+#define tkTEMP    5
+#define tkTRIGGER 6
+#define tkEND     7
+#endif
+
+/*
+** Return TRUE if the given SQL string ends in a semicolon.
+**
+** Special handling is require for CREATE TRIGGER statements.
+** Whenever the CREATE TRIGGER keywords are seen, the statement
+** must end with ";END;".
+**
+** This implementation uses a state machine with 8 states:
+**
+**   (0) INVALID   We have not yet seen a non-whitespace character.
+**
+**   (1) START     At the beginning or end of an SQL statement.  This routine
+**                 returns 1 if it ends in the START state and 0 if it ends
+**                 in any other state.
+**
+**   (2) NORMAL    We are in the middle of statement which ends with a single
+**                 semicolon.
+**
+**   (3) EXPLAIN   The keyword EXPLAIN has been seen at the beginning of 
+**                 a statement.
+**
+**   (4) CREATE    The keyword CREATE has been seen at the beginning of a
+**                 statement, possibly preceded by EXPLAIN and/or followed by
+**                 TEMP or TEMPORARY
+**
+**   (5) TRIGGER   We are in the middle of a trigger definition that must be
+**                 ended by a semicolon, the keyword END, and another semicolon.
+**
+**   (6) SEMI      We've seen the first semicolon in the ";END;" that occurs at
+**                 the end of a trigger definition.
+**
+**   (7) END       We've seen the ";END" of the ";END;" that occurs at the end
+**                 of a trigger definition.
+**
+** Transitions between states above are determined by tokens extracted
+** from the input.  The following tokens are significant:
+**
+**   (0) tkSEMI      A semicolon.
+**   (1) tkWS        Whitespace.
+**   (2) tkOTHER     Any other SQL token.
+**   (3) tkEXPLAIN   The "explain" keyword.
+**   (4) tkCREATE    The "create" keyword.
+**   (5) tkTEMP      The "temp" or "temporary" keyword.
+**   (6) tkTRIGGER   The "trigger" keyword.
+**   (7) tkEND       The "end" keyword.
+**
+** Whitespace never causes a state transition and is always ignored.
+** This means that a SQL string of all whitespace is invalid.
+**
+** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed
+** to recognize the end of a trigger can be omitted.  All we have to do
+** is look for a semicolon that is not part of an string or comment.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *zSql){
+  u8 state = 0;   /* Current state, using numbers defined in header comment */
+  u8 token;       /* Value of the next token */
+
+#ifndef SQLITE_OMIT_TRIGGER
+  /* A complex statement machine used to detect the end of a CREATE TRIGGER
+  ** statement.  This is the normal case.
+  */
+  static const u8 trans[8][8] = {
+                     /* Token:                                                */
+     /* State:       **  SEMI  WS  OTHER  EXPLAIN  CREATE  TEMP  TRIGGER  END */
+     /* 0 INVALID: */ {    1,  0,     2,       3,      4,    2,       2,   2, },
+     /* 1   START: */ {    1,  1,     2,       3,      4,    2,       2,   2, },
+     /* 2  NORMAL: */ {    1,  2,     2,       2,      2,    2,       2,   2, },
+     /* 3 EXPLAIN: */ {    1,  3,     3,       2,      4,    2,       2,   2, },
+     /* 4  CREATE: */ {    1,  4,     2,       2,      2,    4,       5,   2, },
+     /* 5 TRIGGER: */ {    6,  5,     5,       5,      5,    5,       5,   5, },
+     /* 6    SEMI: */ {    6,  6,     5,       5,      5,    5,       5,   7, },
+     /* 7     END: */ {    1,  7,     5,       5,      5,    5,       5,   5, },
+  };
+#else
+  /* If triggers are not supported by this compile then the statement machine
+  ** used to detect the end of a statement is much simpler
+  */
+  static const u8 trans[3][3] = {
+                     /* Token:           */
+     /* State:       **  SEMI  WS  OTHER */
+     /* 0 INVALID: */ {    1,  0,     2, },
+     /* 1   START: */ {    1,  1,     2, },
+     /* 2  NORMAL: */ {    1,  2,     2, },
+  };
+#endif /* SQLITE_OMIT_TRIGGER */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( zSql==0 ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+
+  while( *zSql ){
+    switch( *zSql ){
+      case ';': {  /* A semicolon */
+        token = tkSEMI;
+        break;
+      }
+      case ' ':
+      case '\r':
+      case '\t':
+      case '\n':
+      case '\f': {  /* White space is ignored */
+        token = tkWS;
+        break;
+      }
+      case '/': {   /* C-style comments */
+        if( zSql[1]!='*' ){
+          token = tkOTHER;
+          break;
+        }
+        zSql += 2;
+        while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; }
+        if( zSql[0]==0 ) return 0;
+        zSql++;
+        token = tkWS;
+        break;
+      }
+      case '-': {   /* SQL-style comments from "--" to end of line */
+        if( zSql[1]!='-' ){
+          token = tkOTHER;
+          break;
+        }
+        while( *zSql && *zSql!='\n' ){ zSql++; }
+        if( *zSql==0 ) return state==1;
+        token = tkWS;
+        break;
+      }
+      case '[': {   /* Microsoft-style identifiers in [...] */
+        zSql++;
+        while( *zSql && *zSql!=']' ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      case '`':     /* Grave-accent quoted symbols used by MySQL */
+      case '"':     /* single- and double-quoted strings */
+      case '\'': {
+        int c = *zSql;
+        zSql++;
+        while( *zSql && *zSql!=c ){ zSql++; }
+        if( *zSql==0 ) return 0;
+        token = tkOTHER;
+        break;
+      }
+      default: {
+#ifdef SQLITE_EBCDIC
+        unsigned char c;
+#endif
+        if( IdChar((u8)*zSql) ){
+          /* Keywords and unquoted identifiers */
+          int nId;
+          for(nId=1; IdChar(zSql[nId]); nId++){}
+#ifdef SQLITE_OMIT_TRIGGER
+          token = tkOTHER;
+#else
+          switch( *zSql ){
+            case 'c': case 'C': {
+              if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){
+                token = tkCREATE;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 't': case 'T': {
+              if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){
+                token = tkTRIGGER;
+              }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){
+                token = tkTEMP;
+              }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){
+                token = tkTEMP;
+              }else{
+                token = tkOTHER;
+              }
+              break;
+            }
+            case 'e':  case 'E': {
+              if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){
+                token = tkEND;
+              }else
+#ifndef SQLITE_OMIT_EXPLAIN
+              if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){
+                token = tkEXPLAIN;
+              }else
+#endif
+              {
+                token = tkOTHER;
+              }
+              break;
+            }
+            default: {
+              token = tkOTHER;
+              break;
+            }
+          }
+#endif /* SQLITE_OMIT_TRIGGER */
+          zSql += nId-1;
+        }else{
+          /* Operators and special symbols */
+          token = tkOTHER;
+        }
+        break;
+      }
+    }
+    state = trans[state][token];
+    zSql++;
+  }
+  return state==1;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** This routine is the same as the sqlite3_complete() routine described
+** above, except that the parameter is required to be UTF-16 encoded, not
+** UTF-8.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *zSql){
+  sqlite3_value *pVal;
+  char const *zSql8;
+  int rc;
+
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
+  if( zSql8 ){
+    rc = sqlite3_complete(zSql8);
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3ValueFree(pVal);
+  return rc & 0xff;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+#endif /* SQLITE_OMIT_COMPLETE */
+
+/************** End of complete.c ********************************************/
+/************** Begin file main.c ********************************************/
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** Main file for the SQLite library.  The routines in this file
+** implement the programmer interface to the library.  Routines in
+** other files are for internal use by SQLite and should not be
+** accessed by users of the library.
+*/
+/* #include "sqliteInt.h" */
+
+#ifdef SQLITE_ENABLE_FTS3
+/************** Include fts3.h in the middle of main.c ***********************/
+/************** Begin file fts3.h ********************************************/
+/*
+** 2006 Oct 10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** FTS3 library.  All it does is declare the sqlite3Fts3Init() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3Fts3Init(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+/************** End of fts3.h ************************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_RTREE
+/************** Include rtree.h in the middle of main.c **********************/
+/************** Begin file rtree.h *******************************************/
+/*
+** 2008 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+/************** End of rtree.h ***********************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_ICU
+/************** Include sqliteicu.h in the middle of main.c ******************/
+/************** Begin file sqliteicu.h ***************************************/
+/*
+** 2008 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** ICU extension.  All it does is declare the sqlite3IcuInit() interface.
+*/
+/* #include "sqlite3.h" */
+
+#if 0
+extern "C" {
+#endif  /* __cplusplus */
+
+SQLITE_PRIVATE int sqlite3IcuInit(sqlite3 *db);
+
+#if 0
+}  /* extern "C" */
+#endif  /* __cplusplus */
+
+
+/************** End of sqliteicu.h *******************************************/
+/************** Continuing where we left off in main.c ***********************/
+#endif
+#ifdef SQLITE_ENABLE_JSON1
+SQLITE_PRIVATE int sqlite3Json1Init(sqlite3*);
+#endif
+#ifdef SQLITE_ENABLE_FTS5
+SQLITE_PRIVATE int sqlite3Fts5Init(sqlite3*);
+#endif
+
+#ifndef SQLITE_AMALGAMATION
+/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
+** contains the text of SQLITE_VERSION macro. 
+*/
+SQLITE_API const char sqlite3_version[] = SQLITE_VERSION;
+#endif
+
+/* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
+** a pointer to the to the sqlite3_version[] string constant. 
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void){ return sqlite3_version; }
+
+/* IMPLEMENTATION-OF: R-63124-39300 The sqlite3_sourceid() function returns a
+** pointer to a string constant whose value is the same as the
+** SQLITE_SOURCE_ID C preprocessor macro. 
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }
+
+/* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
+** returns an integer equal to SQLITE_VERSION_NUMBER.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }
+
+/* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
+** zero if and only if SQLite was compiled with mutexing code omitted due to
+** the SQLITE_THREADSAFE compile-time option being set to 0.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
+
+/*
+** When compiling the test fixture or with debugging enabled (on Win32),
+** this variable being set to non-zero will cause OSTRACE macros to emit
+** extra diagnostic information.
+*/
+#ifdef SQLITE_HAVE_OS_TRACE
+# ifndef SQLITE_DEBUG_OS_TRACE
+#   define SQLITE_DEBUG_OS_TRACE 0
+# endif
+  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
+#endif
+
+#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
+/*
+** If the following function pointer is not NULL and if
+** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
+** I/O active are written using this function.  These messages
+** are intended for debugging activity only.
+*/
+SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
+#endif
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** temporary files.
+**
+** See also the "PRAGMA temp_store_directory" SQL command.
+*/
+SQLITE_API char *sqlite3_temp_directory = 0;
+
+/*
+** If the following global variable points to a string which is the
+** name of a directory, then that directory will be used to store
+** all database files specified with a relative pathname.
+**
+** See also the "PRAGMA data_store_directory" SQL command.
+*/
+SQLITE_API char *sqlite3_data_directory = 0;
+
+/*
+** Initialize SQLite.  
+**
+** This routine must be called to initialize the memory allocation,
+** VFS, and mutex subsystems prior to doing any serious work with
+** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
+** this routine will be called automatically by key routines such as
+** sqlite3_open().  
+**
+** This routine is a no-op except on its very first call for the process,
+** or for the first call after a call to sqlite3_shutdown.
+**
+** The first thread to call this routine runs the initialization to
+** completion.  If subsequent threads call this routine before the first
+** thread has finished the initialization process, then the subsequent
+** threads must block until the first thread finishes with the initialization.
+**
+** The first thread might call this routine recursively.  Recursive
+** calls to this routine should not block, of course.  Otherwise the
+** initialization process would never complete.
+**
+** Let X be the first thread to enter this routine.  Let Y be some other
+** thread.  Then while the initial invocation of this routine by X is
+** incomplete, it is required that:
+**
+**    *  Calls to this routine from Y must block until the outer-most
+**       call by X completes.
+**
+**    *  Recursive calls to this routine from thread X return immediately
+**       without blocking.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void){
+  MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
+  int rc;                                      /* Result code */
+#ifdef SQLITE_EXTRA_INIT
+  int bRunExtraInit = 0;                       /* Extra initialization needed */
+#endif
+
+#ifdef SQLITE_OMIT_WSD
+  rc = sqlite3_wsd_init(4096, 24);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+#endif
+
+  /* If the following assert() fails on some obscure processor/compiler
+  ** combination, the work-around is to set the correct pointer
+  ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
+  assert( SQLITE_PTRSIZE==sizeof(char*) );
+
+  /* If SQLite is already completely initialized, then this call
+  ** to sqlite3_initialize() should be a no-op.  But the initialization
+  ** must be complete.  So isInit must not be set until the very end
+  ** of this routine.
+  */
+  if( sqlite3GlobalConfig.isInit ) return SQLITE_OK;
+
+  /* Make sure the mutex subsystem is initialized.  If unable to 
+  ** initialize the mutex subsystem, return early with the error.
+  ** If the system is so sick that we are unable to allocate a mutex,
+  ** there is not much SQLite is going to be able to do.
+  **
+  ** The mutex subsystem must take care of serializing its own
+  ** initialization.
+  */
+  rc = sqlite3MutexInit();
+  if( rc ) return rc;
+
+  /* Initialize the malloc() system and the recursive pInitMutex mutex.
+  ** This operation is protected by the STATIC_MASTER mutex.  Note that
+  ** MutexAlloc() is called for a static mutex prior to initializing the
+  ** malloc subsystem - this implies that the allocation of a static
+  ** mutex must not require support from the malloc subsystem.
+  */
+  MUTEX_LOGIC( pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER); )
+  sqlite3_mutex_enter(pMaster);
+  sqlite3GlobalConfig.isMutexInit = 1;
+  if( !sqlite3GlobalConfig.isMallocInit ){
+    rc = sqlite3MallocInit();
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3GlobalConfig.isMallocInit = 1;
+    if( !sqlite3GlobalConfig.pInitMutex ){
+      sqlite3GlobalConfig.pInitMutex =
+           sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+      if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
+        rc = SQLITE_NOMEM;
+      }
+    }
+  }
+  if( rc==SQLITE_OK ){
+    sqlite3GlobalConfig.nRefInitMutex++;
+  }
+  sqlite3_mutex_leave(pMaster);
+
+  /* If rc is not SQLITE_OK at this point, then either the malloc
+  ** subsystem could not be initialized or the system failed to allocate
+  ** the pInitMutex mutex. Return an error in either case.  */
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* Do the rest of the initialization under the recursive mutex so
+  ** that we will be able to handle recursive calls into
+  ** sqlite3_initialize().  The recursive calls normally come through
+  ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
+  ** recursive calls might also be possible.
+  **
+  ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
+  ** to the xInit method, so the xInit method need not be threadsafe.
+  **
+  ** The following mutex is what serializes access to the appdef pcache xInit
+  ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
+  ** call to sqlite3PcacheInitialize().
+  */
+  sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
+  if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
+    FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
+    sqlite3GlobalConfig.inProgress = 1;
+#ifdef SQLITE_ENABLE_SQLLOG
+    {
+      extern void sqlite3_init_sqllog(void);
+      sqlite3_init_sqllog();
+    }
+#endif
+    memset(pHash, 0, sizeof(sqlite3GlobalFunctions));
+    sqlite3RegisterGlobalFunctions();
+    if( sqlite3GlobalConfig.isPCacheInit==0 ){
+      rc = sqlite3PcacheInitialize();
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3GlobalConfig.isPCacheInit = 1;
+      rc = sqlite3OsInit();
+    }
+    if( rc==SQLITE_OK ){
+      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
+          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
+      sqlite3GlobalConfig.isInit = 1;
+#ifdef SQLITE_EXTRA_INIT
+      bRunExtraInit = 1;
+#endif
+    }
+    sqlite3GlobalConfig.inProgress = 0;
+  }
+  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);
+
+  /* Go back under the static mutex and clean up the recursive
+  ** mutex to prevent a resource leak.
+  */
+  sqlite3_mutex_enter(pMaster);
+  sqlite3GlobalConfig.nRefInitMutex--;
+  if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
+    assert( sqlite3GlobalConfig.nRefInitMutex==0 );
+    sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
+    sqlite3GlobalConfig.pInitMutex = 0;
+  }
+  sqlite3_mutex_leave(pMaster);
+
+  /* The following is just a sanity check to make sure SQLite has
+  ** been compiled correctly.  It is important to run this code, but
+  ** we don't want to run it too often and soak up CPU cycles for no
+  ** reason.  So we run it once during initialization.
+  */
+#ifndef NDEBUG
+#ifndef SQLITE_OMIT_FLOATING_POINT
+  /* This section of code's only "output" is via assert() statements. */
+  if ( rc==SQLITE_OK ){
+    u64 x = (((u64)1)<<63)-1;
+    double y;
+    assert(sizeof(x)==8);
+    assert(sizeof(x)==sizeof(y));
+    memcpy(&y, &x, 8);
+    assert( sqlite3IsNaN(y) );
+  }
+#endif
+#endif
+
+  /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
+  ** compile-time option.
+  */
+#ifdef SQLITE_EXTRA_INIT
+  if( bRunExtraInit ){
+    int SQLITE_EXTRA_INIT(const char*);
+    rc = SQLITE_EXTRA_INIT(0);
+  }
+#endif
+
+  return rc;
+}
+
+/*
+** Undo the effects of sqlite3_initialize().  Must not be called while
+** there are outstanding database connections or memory allocations or
+** while any part of SQLite is otherwise in use in any thread.  This
+** routine is not threadsafe.  But it is safe to invoke this routine
+** on when SQLite is already shut down.  If SQLite is already shut down
+** when this routine is invoked, then this routine is a harmless no-op.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void){
+#ifdef SQLITE_OMIT_WSD
+  int rc = sqlite3_wsd_init(4096, 24);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+#endif
+
+  if( sqlite3GlobalConfig.isInit ){
+#ifdef SQLITE_EXTRA_SHUTDOWN
+    void SQLITE_EXTRA_SHUTDOWN(void);
+    SQLITE_EXTRA_SHUTDOWN();
+#endif
+    sqlite3_os_end();
+    sqlite3_reset_auto_extension();
+    sqlite3GlobalConfig.isInit = 0;
+  }
+  if( sqlite3GlobalConfig.isPCacheInit ){
+    sqlite3PcacheShutdown();
+    sqlite3GlobalConfig.isPCacheInit = 0;
+  }
+  if( sqlite3GlobalConfig.isMallocInit ){
+    sqlite3MallocEnd();
+    sqlite3GlobalConfig.isMallocInit = 0;
+
+#ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
+    /* The heap subsystem has now been shutdown and these values are supposed
+    ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
+    ** which would rely on that heap subsystem; therefore, make sure these
+    ** values cannot refer to heap memory that was just invalidated when the
+    ** heap subsystem was shutdown.  This is only done if the current call to
+    ** this function resulted in the heap subsystem actually being shutdown.
+    */
+    sqlite3_data_directory = 0;
+    sqlite3_temp_directory = 0;
+#endif
+  }
+  if( sqlite3GlobalConfig.isMutexInit ){
+    sqlite3MutexEnd();
+    sqlite3GlobalConfig.isMutexInit = 0;
+  }
+
+  return SQLITE_OK;
+}
+
+/*
+** This API allows applications to modify the global configuration of
+** the SQLite library at run-time.
+**
+** This routine should only be called when there are no outstanding
+** database connections or memory allocations.  This routine is not
+** threadsafe.  Failure to heed these warnings can lead to unpredictable
+** behavior.
+*/
+SQLITE_API int SQLITE_CDECL sqlite3_config(int op, ...){
+  va_list ap;
+  int rc = SQLITE_OK;
+
+  /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
+  ** the SQLite library is in use. */
+  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;
+
+  va_start(ap, op);
+  switch( op ){
+
+    /* Mutex configuration options are only available in a threadsafe
+    ** compile.
+    */
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
+    case SQLITE_CONFIG_SINGLETHREAD: {
+      /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
+      ** Single-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
+    case SQLITE_CONFIG_MULTITHREAD: {
+      /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
+      ** Multi-thread. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
+    case SQLITE_CONFIG_SERIALIZED: {
+      /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
+      ** Serialized. */
+      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
+      sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
+    case SQLITE_CONFIG_MUTEX: {
+      /* Specify an alternative mutex implementation */
+      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
+      break;
+    }
+#endif
+#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
+    case SQLITE_CONFIG_GETMUTEX: {
+      /* Retrieve the current mutex implementation */
+      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_MALLOC: {
+      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The argument specifies alternative
+      ** low-level memory allocation routines to be used in place of the memory
+      ** allocation routines built into SQLite. */
+      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
+      break;
+    }
+    case SQLITE_CONFIG_GETMALLOC: {
+      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
+      ** single argument which is a pointer to an instance of the
+      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
+      ** filled with the currently defined memory allocation routines. */
+      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
+      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
+      break;
+    }
+    case SQLITE_CONFIG_MEMSTATUS: {
+      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
+      ** single argument of type int, interpreted as a boolean, which enables
+      ** or disables the collection of memory allocation statistics. */
+      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_SCRATCH: {
+      /* EVIDENCE-OF: R-08404-60887 There are three arguments to
+      ** SQLITE_CONFIG_SCRATCH: A pointer an 8-byte aligned memory buffer from
+      ** which the scratch allocations will be drawn, the size of each scratch
+      ** allocation (sz), and the maximum number of scratch allocations (N). */
+      sqlite3GlobalConfig.pScratch = va_arg(ap, void*);
+      sqlite3GlobalConfig.szScratch = va_arg(ap, int);
+      sqlite3GlobalConfig.nScratch = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_PAGECACHE: {
+      /* EVIDENCE-OF: R-18761-36601 There are three arguments to
+      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
+      ** the size of each page cache line (sz), and the number of cache lines
+      ** (N). */
+      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
+      sqlite3GlobalConfig.szPage = va_arg(ap, int);
+      sqlite3GlobalConfig.nPage = va_arg(ap, int);
+      break;
+    }
+    case SQLITE_CONFIG_PCACHE_HDRSZ: {
+      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
+      ** a single parameter which is a pointer to an integer and writes into
+      ** that integer the number of extra bytes per page required for each page
+      ** in SQLITE_CONFIG_PAGECACHE. */
+      *va_arg(ap, int*) = 
+          sqlite3HeaderSizeBtree() +
+          sqlite3HeaderSizePcache() +
+          sqlite3HeaderSizePcache1();
+      break;
+    }
+
+    case SQLITE_CONFIG_PCACHE: {
+      /* no-op */
+      break;
+    }
+    case SQLITE_CONFIG_GETPCACHE: {
+      /* now an error */
+      rc = SQLITE_ERROR;
+      break;
+    }
+
+    case SQLITE_CONFIG_PCACHE2: {
+      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. This object specifies the interface to a custom page cache
+      ** implementation. */
+      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
+      break;
+    }
+    case SQLITE_CONFIG_GETPCACHE2: {
+      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
+      ** single argument which is a pointer to an sqlite3_pcache_methods2
+      ** object. SQLite copies of the current page cache implementation into
+      ** that object. */
+      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
+        sqlite3PCacheSetDefault();
+      }
+      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
+      break;
+    }
+
+/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
+** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
+** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
+#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
+    case SQLITE_CONFIG_HEAP: {
+      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
+      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
+      ** number of bytes in the memory buffer, and the minimum allocation size.
+      */
+      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
+      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
+      sqlite3GlobalConfig.mnReq = va_arg(ap, int);
+
+      if( sqlite3GlobalConfig.mnReq<1 ){
+        sqlite3GlobalConfig.mnReq = 1;
+      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
+        /* cap min request size at 2^12 */
+        sqlite3GlobalConfig.mnReq = (1<<12);
+      }
+
+      if( sqlite3GlobalConfig.pHeap==0 ){
+        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
+        ** is NULL, then SQLite reverts to using its default memory allocator
+        ** (the system malloc() implementation), undoing any prior invocation of
+        ** SQLITE_CONFIG_MALLOC.
+        **
+        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
+        ** revert to its default implementation when sqlite3_initialize() is run
+        */
+        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
+      }else{
+        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
+        ** alternative memory allocator is engaged to handle all of SQLites
+        ** memory allocation needs. */
+#ifdef SQLITE_ENABLE_MEMSYS3
+        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
+#endif
+#ifdef SQLITE_ENABLE_MEMSYS5
+        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
+#endif
+      }
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_LOOKASIDE: {
+      sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
+      sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
+      break;
+    }
+    
+    /* Record a pointer to the logger function and its first argument.
+    ** The default is NULL.  Logging is disabled if the function pointer is
+    ** NULL.
+    */
+    case SQLITE_CONFIG_LOG: {
+      /* MSVC is picky about pulling func ptrs from va lists.
+      ** http://support.microsoft.com/kb/47961
+      ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
+      */
+      typedef void(*LOGFUNC_t)(void*,int,const char*);
+      sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
+      sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
+      break;
+    }
+
+    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
+    ** can be changed at start-time using the
+    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
+    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
+    */
+    case SQLITE_CONFIG_URI: {
+      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
+      ** argument of type int. If non-zero, then URI handling is globally
+      ** enabled. If the parameter is zero, then URI handling is globally
+      ** disabled. */
+      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
+      break;
+    }
+
+    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
+      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
+      ** option takes a single integer argument which is interpreted as a
+      ** boolean in order to enable or disable the use of covering indices for
+      ** full table scans in the query optimizer. */
+      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
+      break;
+    }
+
+#ifdef SQLITE_ENABLE_SQLLOG
+    case SQLITE_CONFIG_SQLLOG: {
+      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
+      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
+      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_MMAP_SIZE: {
+      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
+      ** integer (sqlite3_int64) values that are the default mmap size limit
+      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
+      ** mmap size limit. */
+      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
+      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
+      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
+      ** negative, then that argument is changed to its compile-time default.
+      **
+      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
+      ** silently truncated if necessary so that it does not exceed the
+      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
+      ** compile-time option.
+      */
+      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
+        mxMmap = SQLITE_MAX_MMAP_SIZE;
+      }
+      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
+      if( szMmap>mxMmap) szMmap = mxMmap;
+      sqlite3GlobalConfig.mxMmap = mxMmap;
+      sqlite3GlobalConfig.szMmap = szMmap;
+      break;
+    }
+
+#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
+    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
+      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
+      ** unsigned integer value that specifies the maximum size of the created
+      ** heap. */
+      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
+      break;
+    }
+#endif
+
+    case SQLITE_CONFIG_PMASZ: {
+      sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
+      break;
+    }
+
+    default: {
+      rc = SQLITE_ERROR;
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+/*
+** Set up the lookaside buffers for a database connection.
+** Return SQLITE_OK on success.  
+** If lookaside is already active, return SQLITE_BUSY.
+**
+** The sz parameter is the number of bytes in each lookaside slot.
+** The cnt parameter is the number of slots.  If pStart is NULL the
+** space for the lookaside memory is obtained from sqlite3_malloc().
+** If pStart is not NULL then it is sz*cnt bytes of memory to use for
+** the lookaside memory.
+*/
+static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
+#ifndef SQLITE_OMIT_LOOKASIDE
+  void *pStart;
+  if( db->lookaside.nOut ){
+    return SQLITE_BUSY;
+  }
+  /* Free any existing lookaside buffer for this handle before
+  ** allocating a new one so we don't have to have space for 
+  ** both at the same time.
+  */
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
+  ** than a pointer to be useful.
+  */
+  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
+  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
+  if( cnt<0 ) cnt = 0;
+  if( sz==0 || cnt==0 ){
+    sz = 0;
+    pStart = 0;
+  }else if( pBuf==0 ){
+    sqlite3BeginBenignMalloc();
+    pStart = sqlite3Malloc( sz*cnt );  /* IMP: R-61949-35727 */
+    sqlite3EndBenignMalloc();
+    if( pStart ) cnt = sqlite3MallocSize(pStart)/sz;
+  }else{
+    pStart = pBuf;
+  }
+  db->lookaside.pStart = pStart;
+  db->lookaside.pFree = 0;
+  db->lookaside.sz = (u16)sz;
+  if( pStart ){
+    int i;
+    LookasideSlot *p;
+    assert( sz > (int)sizeof(LookasideSlot*) );
+    p = (LookasideSlot*)pStart;
+    for(i=cnt-1; i>=0; i--){
+      p->pNext = db->lookaside.pFree;
+      db->lookaside.pFree = p;
+      p = (LookasideSlot*)&((u8*)p)[sz];
+    }
+    db->lookaside.pEnd = p;
+    db->lookaside.bEnabled = 1;
+    db->lookaside.bMalloced = pBuf==0 ?1:0;
+  }else{
+    db->lookaside.pStart = db;
+    db->lookaside.pEnd = db;
+    db->lookaside.bEnabled = 0;
+    db->lookaside.bMalloced = 0;
+  }
+#endif /* SQLITE_OMIT_LOOKASIDE */
+  return SQLITE_OK;
+}
+
+/*
+** Return the mutex associated with a database connection.
+*/
+SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->mutex;
+}
+
+/*
+** Free up as much memory as we can from the given database
+** connection.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3 *db){
+  int i;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      sqlite3PagerShrink(pPager);
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Flush any dirty pages in the pager-cache for any attached database
+** to disk.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3 *db){
+  int i;
+  int rc = SQLITE_OK;
+  int bSeenBusy = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      rc = sqlite3PagerFlush(pPager);
+      if( rc==SQLITE_BUSY ){
+        bSeenBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
+}
+
+/*
+** Configuration settings for an individual database connection
+*/
+SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3 *db, int op, ...){
+  va_list ap;
+  int rc;
+  va_start(ap, op);
+  switch( op ){
+    case SQLITE_DBCONFIG_LOOKASIDE: {
+      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
+      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
+      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
+      rc = setupLookaside(db, pBuf, sz, cnt);
+      break;
+    }
+    default: {
+      static const struct {
+        int op;      /* The opcode */
+        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
+      } aFlagOp[] = {
+        { SQLITE_DBCONFIG_ENABLE_FKEY,    SQLITE_ForeignKeys    },
+        { SQLITE_DBCONFIG_ENABLE_TRIGGER, SQLITE_EnableTrigger  },
+      };
+      unsigned int i;
+      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
+      for(i=0; i<ArraySize(aFlagOp); i++){
+        if( aFlagOp[i].op==op ){
+          int onoff = va_arg(ap, int);
+          int *pRes = va_arg(ap, int*);
+          int oldFlags = db->flags;
+          if( onoff>0 ){
+            db->flags |= aFlagOp[i].mask;
+          }else if( onoff==0 ){
+            db->flags &= ~aFlagOp[i].mask;
+          }
+          if( oldFlags!=db->flags ){
+            sqlite3ExpirePreparedStatements(db);
+          }
+          if( pRes ){
+            *pRes = (db->flags & aFlagOp[i].mask)!=0;
+          }
+          rc = SQLITE_OK;
+          break;
+        }
+      }
+      break;
+    }
+  }
+  va_end(ap);
+  return rc;
+}
+
+
+/*
+** Return true if the buffer z[0..n-1] contains all spaces.
+*/
+static int allSpaces(const char *z, int n){
+  while( n>0 && z[n-1]==' ' ){ n--; }
+  return n==0;
+}
+
+/*
+** This is the default collating function named "BINARY" which is always
+** available.
+**
+** If the padFlag argument is not NULL then space padding at the end
+** of strings is ignored.  This implements the RTRIM collation.
+*/
+static int binCollFunc(
+  void *padFlag,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int rc, n;
+  n = nKey1<nKey2 ? nKey1 : nKey2;
+  /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
+  ** strings byte by byte using the memcmp() function from the standard C
+  ** library. */
+  rc = memcmp(pKey1, pKey2, n);
+  if( rc==0 ){
+    if( padFlag
+     && allSpaces(((char*)pKey1)+n, nKey1-n)
+     && allSpaces(((char*)pKey2)+n, nKey2-n)
+    ){
+      /* EVIDENCE-OF: R-31624-24737 RTRIM is like BINARY except that extra
+      ** spaces at the end of either string do not change the result. In other
+      ** words, strings will compare equal to one another as long as they
+      ** differ only in the number of spaces at the end.
+      */
+    }else{
+      rc = nKey1 - nKey2;
+    }
+  }
+  return rc;
+}
+
+/*
+** Another built-in collating sequence: NOCASE. 
+**
+** This collating sequence is intended to be used for "case independent
+** comparison". SQLite's knowledge of upper and lower case equivalents
+** extends only to the 26 characters used in the English language.
+**
+** At the moment there is only a UTF-8 implementation.
+*/
+static int nocaseCollatingFunc(
+  void *NotUsed,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  int r = sqlite3StrNICmp(
+      (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
+  UNUSED_PARAMETER(NotUsed);
+  if( 0==r ){
+    r = nKey1-nKey2;
+  }
+  return r;
+}
+
+/*
+** Return the ROWID of the most recent insert
+*/
+SQLITE_API sqlite_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->lastRowid;
+}
+
+/*
+** Return the number of changes in the most recent call to sqlite3_exec().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->nChange;
+}
+
+/*
+** Return the number of changes since the database handle was opened.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->nTotalChange;
+}
+
+/*
+** Close all open savepoints. This function only manipulates fields of the
+** database handle object, it does not close any savepoints that may be open
+** at the b-tree/pager level.
+*/
+SQLITE_PRIVATE void sqlite3CloseSavepoints(sqlite3 *db){
+  while( db->pSavepoint ){
+    Savepoint *pTmp = db->pSavepoint;
+    db->pSavepoint = pTmp->pNext;
+    sqlite3DbFree(db, pTmp);
+  }
+  db->nSavepoint = 0;
+  db->nStatement = 0;
+  db->isTransactionSavepoint = 0;
+}
+
+/*
+** Invoke the destructor function associated with FuncDef p, if any. Except,
+** if this is not the last copy of the function, do not invoke it. Multiple
+** copies of a single function are created when create_function() is called
+** with SQLITE_ANY as the encoding.
+*/
+static void functionDestroy(sqlite3 *db, FuncDef *p){
+  FuncDestructor *pDestructor = p->pDestructor;
+  if( pDestructor ){
+    pDestructor->nRef--;
+    if( pDestructor->nRef==0 ){
+      pDestructor->xDestroy(pDestructor->pUserData);
+      sqlite3DbFree(db, pDestructor);
+    }
+  }
+}
+
+/*
+** Disconnect all sqlite3_vtab objects that belong to database connection
+** db. This is called when db is being closed.
+*/
+static void disconnectAllVtab(sqlite3 *db){
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  int i;
+  HashElem *p;
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Schema *pSchema = db->aDb[i].pSchema;
+    if( db->aDb[i].pSchema ){
+      for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
+        Table *pTab = (Table *)sqliteHashData(p);
+        if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
+      }
+    }
+  }
+  for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
+    Module *pMod = (Module *)sqliteHashData(p);
+    if( pMod->pEpoTab ){
+      sqlite3VtabDisconnect(db, pMod->pEpoTab);
+    }
+  }
+  sqlite3VtabUnlockList(db);
+  sqlite3BtreeLeaveAll(db);
+#else
+  UNUSED_PARAMETER(db);
+#endif
+}
+
+/*
+** Return TRUE if database connection db has unfinalized prepared
+** statements or unfinished sqlite3_backup objects.  
+*/
+static int connectionIsBusy(sqlite3 *db){
+  int j;
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( db->pVdbe ) return 1;
+  for(j=0; j<db->nDb; j++){
+    Btree *pBt = db->aDb[j].pBt;
+    if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Close an existing SQLite database
+*/
+static int sqlite3Close(sqlite3 *db, int forceZombie){
+  if( !db ){
+    /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
+    ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
+    return SQLITE_OK;
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  sqlite3_mutex_enter(db->mutex);
+
+  /* Force xDisconnect calls on all virtual tables */
+  disconnectAllVtab(db);
+
+  /* If a transaction is open, the disconnectAllVtab() call above
+  ** will not have called the xDisconnect() method on any virtual
+  ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
+  ** call will do so. We need to do this before the check for active
+  ** SQL statements below, as the v-table implementation may be storing
+  ** some prepared statements internally.
+  */
+  sqlite3VtabRollback(db);
+
+  /* Legacy behavior (sqlite3_close() behavior) is to return
+  ** SQLITE_BUSY if the connection can not be closed immediately.
+  */
+  if( !forceZombie && connectionIsBusy(db) ){
+    sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
+       "statements or unfinished backups");
+    sqlite3_mutex_leave(db->mutex);
+    return SQLITE_BUSY;
+  }
+
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Closing the handle. Fourth parameter is passed the value 2. */
+    sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
+  }
+#endif
+
+  /* Convert the connection into a zombie and then close it.
+  */
+  db->magic = SQLITE_MAGIC_ZOMBIE;
+  sqlite3LeaveMutexAndCloseZombie(db);
+  return SQLITE_OK;
+}
+
+/*
+** Two variations on the public interface for closing a database
+** connection. The sqlite3_close() version returns SQLITE_BUSY and
+** leaves the connection option if there are unfinalized prepared
+** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
+** version forces the connection to become a zombie if there are
+** unclosed resources, and arranges for deallocation when the last
+** prepare statement or sqlite3_backup closes.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
+SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }
+
+
+/*
+** Close the mutex on database connection db.
+**
+** Furthermore, if database connection db is a zombie (meaning that there
+** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
+** every sqlite3_stmt has now been finalized and every sqlite3_backup has
+** finished, then free all resources.
+*/
+SQLITE_PRIVATE void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
+  HashElem *i;                    /* Hash table iterator */
+  int j;
+
+  /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
+  ** or if the connection has not yet been closed by sqlite3_close_v2(),
+  ** then just leave the mutex and return.
+  */
+  if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
+    sqlite3_mutex_leave(db->mutex);
+    return;
+  }
+
+  /* If we reach this point, it means that the database connection has
+  ** closed all sqlite3_stmt and sqlite3_backup objects and has been
+  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
+  ** go ahead and free all resources.
+  */
+
+  /* If a transaction is open, roll it back. This also ensures that if
+  ** any database schemas have been modified by an uncommitted transaction
+  ** they are reset. And that the required b-tree mutex is held to make
+  ** the pager rollback and schema reset an atomic operation. */
+  sqlite3RollbackAll(db, SQLITE_OK);
+
+  /* Free any outstanding Savepoint structures. */
+  sqlite3CloseSavepoints(db);
+
+  /* Close all database connections */
+  for(j=0; j<db->nDb; j++){
+    struct Db *pDb = &db->aDb[j];
+    if( pDb->pBt ){
+      sqlite3BtreeClose(pDb->pBt);
+      pDb->pBt = 0;
+      if( j!=1 ){
+        pDb->pSchema = 0;
+      }
+    }
+  }
+  /* Clear the TEMP schema separately and last */
+  if( db->aDb[1].pSchema ){
+    sqlite3SchemaClear(db->aDb[1].pSchema);
+  }
+  sqlite3VtabUnlockList(db);
+
+  /* Free up the array of auxiliary databases */
+  sqlite3CollapseDatabaseArray(db);
+  assert( db->nDb<=2 );
+  assert( db->aDb==db->aDbStatic );
+
+  /* Tell the code in notify.c that the connection no longer holds any
+  ** locks and does not require any further unlock-notify callbacks.
+  */
+  sqlite3ConnectionClosed(db);
+
+  for(j=0; j<ArraySize(db->aFunc.a); j++){
+    FuncDef *pNext, *pHash, *p;
+    for(p=db->aFunc.a[j]; p; p=pHash){
+      pHash = p->pHash;
+      while( p ){
+        functionDestroy(db, p);
+        pNext = p->pNext;
+        sqlite3DbFree(db, p);
+        p = pNext;
+      }
+    }
+  }
+  for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
+    CollSeq *pColl = (CollSeq *)sqliteHashData(i);
+    /* Invoke any destructors registered for collation sequence user data. */
+    for(j=0; j<3; j++){
+      if( pColl[j].xDel ){
+        pColl[j].xDel(pColl[j].pUser);
+      }
+    }
+    sqlite3DbFree(db, pColl);
+  }
+  sqlite3HashClear(&db->aCollSeq);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
+    Module *pMod = (Module *)sqliteHashData(i);
+    if( pMod->xDestroy ){
+      pMod->xDestroy(pMod->pAux);
+    }
+    sqlite3VtabEponymousTableClear(db, pMod);
+    sqlite3DbFree(db, pMod);
+  }
+  sqlite3HashClear(&db->aModule);
+#endif
+
+  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
+  sqlite3ValueFree(db->pErr);
+  sqlite3CloseExtensions(db);
+#if SQLITE_USER_AUTHENTICATION
+  sqlite3_free(db->auth.zAuthUser);
+  sqlite3_free(db->auth.zAuthPW);
+#endif
+
+  db->magic = SQLITE_MAGIC_ERROR;
+
+  /* The temp-database schema is allocated differently from the other schema
+  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
+  ** So it needs to be freed here. Todo: Why not roll the temp schema into
+  ** the same sqliteMalloc() as the one that allocates the database 
+  ** structure?
+  */
+  sqlite3DbFree(db, db->aDb[1].pSchema);
+  sqlite3_mutex_leave(db->mutex);
+  db->magic = SQLITE_MAGIC_CLOSED;
+  sqlite3_mutex_free(db->mutex);
+  assert( db->lookaside.nOut==0 );  /* Fails on a lookaside memory leak */
+  if( db->lookaside.bMalloced ){
+    sqlite3_free(db->lookaside.pStart);
+  }
+  sqlite3_free(db);
+}
+
+/*
+** Rollback all database files.  If tripCode is not SQLITE_OK, then
+** any write cursors are invalidated ("tripped" - as in "tripping a circuit
+** breaker") and made to return tripCode if there are any further
+** attempts to use that cursor.  Read cursors remain open and valid
+** but are "saved" in case the table pages are moved around.
+*/
+SQLITE_PRIVATE void sqlite3RollbackAll(sqlite3 *db, int tripCode){
+  int i;
+  int inTrans = 0;
+  int schemaChange;
+  assert( sqlite3_mutex_held(db->mutex) );
+  sqlite3BeginBenignMalloc();
+
+  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
+  ** This is important in case the transaction being rolled back has
+  ** modified the database schema. If the b-tree mutexes are not taken
+  ** here, then another shared-cache connection might sneak in between
+  ** the database rollback and schema reset, which can cause false
+  ** corruption reports in some cases.  */
+  sqlite3BtreeEnterAll(db);
+  schemaChange = (db->flags & SQLITE_InternChanges)!=0 && db->init.busy==0;
+
+  for(i=0; i<db->nDb; i++){
+    Btree *p = db->aDb[i].pBt;
+    if( p ){
+      if( sqlite3BtreeIsInTrans(p) ){
+        inTrans = 1;
+      }
+      sqlite3BtreeRollback(p, tripCode, !schemaChange);
+    }
+  }
+  sqlite3VtabRollback(db);
+  sqlite3EndBenignMalloc();
+
+  if( (db->flags&SQLITE_InternChanges)!=0 && db->init.busy==0 ){
+    sqlite3ExpirePreparedStatements(db);
+    sqlite3ResetAllSchemasOfConnection(db);
+  }
+  sqlite3BtreeLeaveAll(db);
+
+  /* Any deferred constraint violations have now been resolved. */
+  db->nDeferredCons = 0;
+  db->nDeferredImmCons = 0;
+  db->flags &= ~SQLITE_DeferFKs;
+
+  /* If one has been configured, invoke the rollback-hook callback */
+  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
+    db->xRollbackCallback(db->pRollbackArg);
+  }
+}
+
+/*
+** Return a static string containing the name corresponding to the error code
+** specified in the argument.
+*/
+#if defined(SQLITE_NEED_ERR_NAME)
+SQLITE_PRIVATE const char *sqlite3ErrName(int rc){
+  const char *zName = 0;
+  int i, origRc = rc;
+  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
+    switch( rc ){
+      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
+      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
+      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
+      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
+      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
+      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
+      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
+      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
+      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
+      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
+      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
+      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
+      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
+      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
+      case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
+      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
+      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
+      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
+      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
+      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
+      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
+      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
+      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
+      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
+      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
+      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
+      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
+      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
+      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
+      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
+      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
+      case SQLITE_IOERR_CHECKRESERVEDLOCK:
+                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
+      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
+      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
+      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
+      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
+      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
+      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
+      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
+      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
+      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
+      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
+      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
+      case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
+      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
+      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
+      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
+      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
+      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
+      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
+      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
+      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
+      case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
+      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
+      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
+      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
+      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
+      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
+      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
+      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
+      case SQLITE_CONSTRAINT_FOREIGNKEY:
+                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
+      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
+      case SQLITE_CONSTRAINT_PRIMARYKEY:
+                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
+      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
+      case SQLITE_CONSTRAINT_COMMITHOOK:
+                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
+      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
+      case SQLITE_CONSTRAINT_FUNCTION:
+                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
+      case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
+      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
+      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
+      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
+      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
+      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
+      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
+      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
+      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
+      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
+      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
+      case SQLITE_NOTICE_RECOVER_ROLLBACK:
+                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
+      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
+      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
+      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
+    }
+  }
+  if( zName==0 ){
+    static char zBuf[50];
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
+    zName = zBuf;
+  }
+  return zName;
+}
+#endif
+
+/*
+** Return a static string that describes the kind of error specified in the
+** argument.
+*/
+SQLITE_PRIVATE const char *sqlite3ErrStr(int rc){
+  static const char* const aMsg[] = {
+    /* SQLITE_OK          */ "not an error",
+    /* SQLITE_ERROR       */ "SQL logic error or missing database",
+    /* SQLITE_INTERNAL    */ 0,
+    /* SQLITE_PERM        */ "access permission denied",
+    /* SQLITE_ABORT       */ "callback requested query abort",
+    /* SQLITE_BUSY        */ "database is locked",
+    /* SQLITE_LOCKED      */ "database table is locked",
+    /* SQLITE_NOMEM       */ "out of memory",
+    /* SQLITE_READONLY    */ "attempt to write a readonly database",
+    /* SQLITE_INTERRUPT   */ "interrupted",
+    /* SQLITE_IOERR       */ "disk I/O error",
+    /* SQLITE_CORRUPT     */ "database disk image is malformed",
+    /* SQLITE_NOTFOUND    */ "unknown operation",
+    /* SQLITE_FULL        */ "database or disk is full",
+    /* SQLITE_CANTOPEN    */ "unable to open database file",
+    /* SQLITE_PROTOCOL    */ "locking protocol",
+    /* SQLITE_EMPTY       */ "table contains no data",
+    /* SQLITE_SCHEMA      */ "database schema has changed",
+    /* SQLITE_TOOBIG      */ "string or blob too big",
+    /* SQLITE_CONSTRAINT  */ "constraint failed",
+    /* SQLITE_MISMATCH    */ "datatype mismatch",
+    /* SQLITE_MISUSE      */ "library routine called out of sequence",
+    /* SQLITE_NOLFS       */ "large file support is disabled",
+    /* SQLITE_AUTH        */ "authorization denied",
+    /* SQLITE_FORMAT      */ "auxiliary database format error",
+    /* SQLITE_RANGE       */ "bind or column index out of range",
+    /* SQLITE_NOTADB      */ "file is encrypted or is not a database",
+  };
+  const char *zErr = "unknown error";
+  switch( rc ){
+    case SQLITE_ABORT_ROLLBACK: {
+      zErr = "abort due to ROLLBACK";
+      break;
+    }
+    default: {
+      rc &= 0xff;
+      if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
+        zErr = aMsg[rc];
+      }
+      break;
+    }
+  }
+  return zErr;
+}
+
+/*
+** This routine implements a busy callback that sleeps and tries
+** again until a timeout value is reached.  The timeout value is
+** an integer number of milliseconds passed in as the first
+** argument.
+*/
+static int sqliteDefaultBusyCallback(
+ void *ptr,               /* Database connection */
+ int count                /* Number of times table has been busy */
+){
+#if SQLITE_OS_WIN || HAVE_USLEEP
+  static const u8 delays[] =
+     { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
+  static const u8 totals[] =
+     { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
+# define NDELAY ArraySize(delays)
+  sqlite3 *db = (sqlite3 *)ptr;
+  int timeout = db->busyTimeout;
+  int delay, prior;
+
+  assert( count>=0 );
+  if( count < NDELAY ){
+    delay = delays[count];
+    prior = totals[count];
+  }else{
+    delay = delays[NDELAY-1];
+    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
+  }
+  if( prior + delay > timeout ){
+    delay = timeout - prior;
+    if( delay<=0 ) return 0;
+  }
+  sqlite3OsSleep(db->pVfs, delay*1000);
+  return 1;
+#else
+  sqlite3 *db = (sqlite3 *)ptr;
+  int timeout = ((sqlite3 *)ptr)->busyTimeout;
+  if( (count+1)*1000 > timeout ){
+    return 0;
+  }
+  sqlite3OsSleep(db->pVfs, 1000000);
+  return 1;
+#endif
+}
+
+/*
+** Invoke the given busy handler.
+**
+** This routine is called when an operation failed with a lock.
+** If this routine returns non-zero, the lock is retried.  If it
+** returns 0, the operation aborts with an SQLITE_BUSY error.
+*/
+SQLITE_PRIVATE int sqlite3InvokeBusyHandler(BusyHandler *p){
+  int rc;
+  if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
+  rc = p->xFunc(p->pArg, p->nBusy);
+  if( rc==0 ){
+    p->nBusy = -1;
+  }else{
+    p->nBusy++;
+  }
+  return rc; 
+}
+
+/*
+** This routine sets the busy callback for an Sqlite database to the
+** given callback function with the given argument.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(
+  sqlite3 *db,
+  int (*xBusy)(void*,int),
+  void *pArg
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->busyHandler.xFunc = xBusy;
+  db->busyHandler.pArg = pArg;
+  db->busyHandler.nBusy = 0;
+  db->busyTimeout = 0;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+/*
+** This routine sets the progress callback for an Sqlite database to the
+** given callback function with the given argument. The progress callback will
+** be invoked every nOps opcodes.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(
+  sqlite3 *db, 
+  int nOps,
+  int (*xProgress)(void*), 
+  void *pArg
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( nOps>0 ){
+    db->xProgress = xProgress;
+    db->nProgressOps = (unsigned)nOps;
+    db->pProgressArg = pArg;
+  }else{
+    db->xProgress = 0;
+    db->nProgressOps = 0;
+    db->pProgressArg = 0;
+  }
+  sqlite3_mutex_leave(db->mutex);
+}
+#endif
+
+
+/*
+** This routine installs a default busy handler that waits for the
+** specified number of milliseconds before returning 0.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3 *db, int ms){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  if( ms>0 ){
+    sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void*)db);
+    db->busyTimeout = ms;
+  }else{
+    sqlite3_busy_handler(db, 0, 0);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Cause any pending operation to stop at its earliest opportunity.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return;
+  }
+#endif
+  db->u1.isInterrupted = 1;
+}
+
+
+/*
+** This function is exactly the same as sqlite3_create_function(), except
+** that it is designed to be called by internal code. The difference is
+** that if a malloc() fails in sqlite3_create_function(), an error code
+** is returned and the mallocFailed flag cleared. 
+*/
+SQLITE_PRIVATE int sqlite3CreateFunc(
+  sqlite3 *db,
+  const char *zFunctionName,
+  int nArg,
+  int enc,
+  void *pUserData,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*),
+  FuncDestructor *pDestructor
+){
+  FuncDef *p;
+  int nName;
+  int extraFlags;
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( zFunctionName==0 ||
+      (xFunc && (xFinal || xStep)) || 
+      (!xFunc && (xFinal && !xStep)) ||
+      (!xFunc && (!xFinal && xStep)) ||
+      (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG) ||
+      (255<(nName = sqlite3Strlen30( zFunctionName))) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+
+  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
+  extraFlags = enc &  SQLITE_DETERMINISTIC;
+  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
+  
+#ifndef SQLITE_OMIT_UTF16
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  **
+  ** If SQLITE_ANY is specified, add three versions of the function
+  ** to the hash table.
+  */
+  if( enc==SQLITE_UTF16 ){
+    enc = SQLITE_UTF16NATIVE;
+  }else if( enc==SQLITE_ANY ){
+    int rc;
+    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
+         pUserData, xFunc, xStep, xFinal, pDestructor);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
+          pUserData, xFunc, xStep, xFinal, pDestructor);
+    }
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    enc = SQLITE_UTF16BE;
+  }
+#else
+  enc = SQLITE_UTF8;
+#endif
+  
+  /* Check if an existing function is being overridden or deleted. If so,
+  ** and there are active VMs, then return SQLITE_BUSY. If a function
+  ** is being overridden/deleted but there are no active VMs, allow the
+  ** operation to continue but invalidate all precompiled statements.
+  */
+  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
+  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==enc && p->nArg==nArg ){
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
+        "unable to delete/modify user-function due to active statements");
+      assert( !db->mallocFailed );
+      return SQLITE_BUSY;
+    }else{
+      sqlite3ExpirePreparedStatements(db);
+    }
+  }
+
+  p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 1);
+  assert(p || db->mallocFailed);
+  if( !p ){
+    return SQLITE_NOMEM;
+  }
+
+  /* If an older version of the function with a configured destructor is
+  ** being replaced invoke the destructor function here. */
+  functionDestroy(db, p);
+
+  if( pDestructor ){
+    pDestructor->nRef++;
+  }
+  p->pDestructor = pDestructor;
+  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
+  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
+  p->xFunc = xFunc;
+  p->xStep = xStep;
+  p->xFinalize = xFinal;
+  p->pUserData = pUserData;
+  p->nArg = (u16)nArg;
+  return SQLITE_OK;
+}
+
+/*
+** Create new user functions.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
+  sqlite3 *db,
+  const char *zFunc,
+  int nArg,
+  int enc,
+  void *p,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*)
+){
+  return sqlite3_create_function_v2(db, zFunc, nArg, enc, p, xFunc, xStep,
+                                    xFinal, 0);
+}
+
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
+  sqlite3 *db,
+  const char *zFunc,
+  int nArg,
+  int enc,
+  void *p,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value **),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
+  void (*xFinal)(sqlite3_context*),
+  void (*xDestroy)(void *)
+){
+  int rc = SQLITE_ERROR;
+  FuncDestructor *pArg = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( xDestroy ){
+    pArg = (FuncDestructor *)sqlite3DbMallocZero(db, sizeof(FuncDestructor));
+    if( !pArg ){
+      xDestroy(p);
+      goto out;
+    }
+    pArg->xDestroy = xDestroy;
+    pArg->pUserData = p;
+  }
+  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, xFunc, xStep, xFinal, pArg);
+  if( pArg && pArg->nRef==0 ){
+    assert( rc!=SQLITE_OK );
+    xDestroy(p);
+    sqlite3DbFree(db, pArg);
+  }
+
+ out:
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
+  sqlite3 *db,
+  const void *zFunctionName,
+  int nArg,
+  int eTextRep,
+  void *p,
+  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
+  void (*xFinal)(sqlite3_context*)
+){
+  int rc;
+  char *zFunc8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
+  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal,0);
+  sqlite3DbFree(db, zFunc8);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif
+
+
+/*
+** Declare that a function has been overloaded by a virtual table.
+**
+** If the function already exists as a regular global function, then
+** this routine is a no-op.  If the function does not exist, then create
+** a new one that always throws a run-time error.  
+**
+** When virtual tables intend to provide an overloaded function, they
+** should call this routine to make sure the global function exists.
+** A global function must exist in order for name resolution to work
+** properly.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(
+  sqlite3 *db,
+  const char *zName,
+  int nArg
+){
+  int nName = sqlite3Strlen30(zName);
+  int rc = SQLITE_OK;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( sqlite3FindFunction(db, zName, nName, nArg, SQLITE_UTF8, 0)==0 ){
+    rc = sqlite3CreateFunc(db, zName, nArg, SQLITE_UTF8,
+                           0, sqlite3InvalidFunction, 0, 0, 0);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_TRACE
+/*
+** Register a trace function.  The pArg from the previously registered trace
+** is returned.  
+**
+** A NULL trace function means that no tracing is executes.  A non-NULL
+** trace is a pointer to a function that is invoked at the start of each
+** SQL statement.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3 *db, void (*xTrace)(void*,const char*), void *pArg){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pTraceArg;
+  db->xTrace = xTrace;
+  db->pTraceArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+/*
+** Register a profile function.  The pArg from the previously registered 
+** profile function is returned.  
+**
+** A NULL profile function means that no profiling is executes.  A non-NULL
+** profile is a pointer to a function that is invoked at the conclusion of
+** each SQL statement that is run.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_profile(
+  sqlite3 *db,
+  void (*xProfile)(void*,const char*,sqlite_uint64),
+  void *pArg
+){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pProfileArg;
+  db->xProfile = xProfile;
+  db->pProfileArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+#endif /* SQLITE_OMIT_TRACE */
+
+/*
+** Register a function to be invoked when a transaction commits.
+** If the invoked function returns non-zero, then the commit becomes a
+** rollback.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  int (*xCallback)(void*),  /* Function to invoke on each commit */
+  void *pArg                /* Argument to the function */
+){
+  void *pOld;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pOld = db->pCommitArg;
+  db->xCommitCallback = xCallback;
+  db->pCommitArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pOld;
+}
+
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pUpdateArg;
+  db->xUpdateCallback = xCallback;
+  db->pUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+/*
+** Register a callback to be invoked each time a transaction is rolled
+** back by this database connection.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void (*xCallback)(void*), /* Callback function */
+  void *pArg                /* Argument to the function */
+){
+  void *pRet;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pRollbackArg;
+  db->xRollbackCallback = xCallback;
+  db->pRollbackArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+
+#ifndef SQLITE_OMIT_WAL
+/*
+** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
+** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
+** is greater than sqlite3.pWalArg cast to an integer (the value configured by
+** wal_autocheckpoint()).
+*/ 
+SQLITE_PRIVATE int sqlite3WalDefaultHook(
+  void *pClientData,     /* Argument */
+  sqlite3 *db,           /* Connection */
+  const char *zDb,       /* Database */
+  int nFrame             /* Size of WAL */
+){
+  if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
+    sqlite3BeginBenignMalloc();
+    sqlite3_wal_checkpoint(db, zDb);
+    sqlite3EndBenignMalloc();
+  }
+  return SQLITE_OK;
+}
+#endif /* SQLITE_OMIT_WAL */
+
+/*
+** Configure an sqlite3_wal_hook() callback to automatically checkpoint
+** a database after committing a transaction if there are nFrame or
+** more frames in the log file. Passing zero or a negative value as the
+** nFrame parameter disables automatic checkpoints entirely.
+**
+** The callback registered by this function replaces any existing callback
+** registered using sqlite3_wal_hook(). Likewise, registering a callback
+** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
+** configured by this function.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
+#ifdef SQLITE_OMIT_WAL
+  UNUSED_PARAMETER(db);
+  UNUSED_PARAMETER(nFrame);
+#else
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  if( nFrame>0 ){
+    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
+  }else{
+    sqlite3_wal_hook(db, 0, 0);
+  }
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Register a callback to be invoked each time a transaction is written
+** into the write-ahead-log by this database connection.
+*/
+SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
+  sqlite3 *db,                    /* Attach the hook to this db handle */
+  int(*xCallback)(void *, sqlite3*, const char*, int),
+  void *pArg                      /* First argument passed to xCallback() */
+){
+#ifndef SQLITE_OMIT_WAL
+  void *pRet;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pWalArg;
+  db->xWalCallback = xCallback;
+  db->pWalArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+#else
+  return 0;
+#endif
+}
+
+/*
+** Checkpoint database zDb.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of attached database (or NULL) */
+  int eMode,                      /* SQLITE_CHECKPOINT_* value */
+  int *pnLog,                     /* OUT: Size of WAL log in frames */
+  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
+){
+#ifdef SQLITE_OMIT_WAL
+  return SQLITE_OK;
+#else
+  int rc;                         /* Return code */
+  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+
+  /* Initialize the output variables to -1 in case an error occurs. */
+  if( pnLog ) *pnLog = -1;
+  if( pnCkpt ) *pnCkpt = -1;
+
+  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
+  assert( SQLITE_CHECKPOINT_FULL==1 );
+  assert( SQLITE_CHECKPOINT_RESTART==2 );
+  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
+  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
+    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
+    ** mode: */
+    return SQLITE_MISUSE;
+  }
+
+  sqlite3_mutex_enter(db->mutex);
+  if( zDb && zDb[0] ){
+    iDb = sqlite3FindDbName(db, zDb);
+  }
+  if( iDb<0 ){
+    rc = SQLITE_ERROR;
+    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
+  }else{
+    db->busyHandler.nBusy = 0;
+    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
+    sqlite3Error(db, rc);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+#endif
+}
+
+
+/*
+** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
+** to contains a zero-length string, all attached databases are 
+** checkpointed.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
+  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
+  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
+  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
+}
+
+#ifndef SQLITE_OMIT_WAL
+/*
+** Run a checkpoint on database iDb. This is a no-op if database iDb is
+** not currently open in WAL mode.
+**
+** If a transaction is open on the database being checkpointed, this 
+** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
+** an error occurs while running the checkpoint, an SQLite error code is 
+** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
+**
+** The mutex on database handle db should be held by the caller. The mutex
+** associated with the specific b-tree being checkpointed is taken by
+** this function while the checkpoint is running.
+**
+** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
+** checkpointed. If an error is encountered it is returned immediately -
+** no attempt is made to checkpoint any remaining databases.
+**
+** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
+*/
+SQLITE_PRIVATE int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
+  int rc = SQLITE_OK;             /* Return code */
+  int i;                          /* Used to iterate through attached dbs */
+  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */
+
+  assert( sqlite3_mutex_held(db->mutex) );
+  assert( !pnLog || *pnLog==-1 );
+  assert( !pnCkpt || *pnCkpt==-1 );
+
+  for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
+    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
+      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
+      pnLog = 0;
+      pnCkpt = 0;
+      if( rc==SQLITE_BUSY ){
+        bBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+
+  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
+}
+#endif /* SQLITE_OMIT_WAL */
+
+/*
+** This function returns true if main-memory should be used instead of
+** a temporary file for transient pager files and statement journals.
+** The value returned depends on the value of db->temp_store (runtime
+** parameter) and the compile time value of SQLITE_TEMP_STORE. The
+** following table describes the relationship between these two values
+** and this functions return value.
+**
+**   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
+**   -----------------     --------------     ------------------------------
+**   0                     any                file      (return 0)
+**   1                     1                  file      (return 0)
+**   1                     2                  memory    (return 1)
+**   1                     0                  file      (return 0)
+**   2                     1                  file      (return 0)
+**   2                     2                  memory    (return 1)
+**   2                     0                  memory    (return 1)
+**   3                     any                memory    (return 1)
+*/
+SQLITE_PRIVATE int sqlite3TempInMemory(const sqlite3 *db){
+#if SQLITE_TEMP_STORE==1
+  return ( db->temp_store==2 );
+#endif
+#if SQLITE_TEMP_STORE==2
+  return ( db->temp_store!=1 );
+#endif
+#if SQLITE_TEMP_STORE==3
+  UNUSED_PARAMETER(db);
+  return 1;
+#endif
+#if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
+  UNUSED_PARAMETER(db);
+  return 0;
+#endif
+}
+
+/*
+** Return UTF-8 encoded English language explanation of the most recent
+** error.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3 *db){
+  const char *z;
+  if( !db ){
+    return sqlite3ErrStr(SQLITE_NOMEM);
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
+  }
+  sqlite3_mutex_enter(db->mutex);
+  if( db->mallocFailed ){
+    z = sqlite3ErrStr(SQLITE_NOMEM);
+  }else{
+    testcase( db->pErr==0 );
+    z = (char*)sqlite3_value_text(db->pErr);
+    assert( !db->mallocFailed );
+    if( z==0 ){
+      z = sqlite3ErrStr(db->errCode);
+    }
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Return UTF-16 encoded English language explanation of the most recent
+** error.
+*/
+SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3 *db){
+  static const u16 outOfMem[] = {
+    'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
+  };
+  static const u16 misuse[] = {
+    'l', 'i', 'b', 'r', 'a', 'r', 'y', ' ', 
+    'r', 'o', 'u', 't', 'i', 'n', 'e', ' ', 
+    'c', 'a', 'l', 'l', 'e', 'd', ' ', 
+    'o', 'u', 't', ' ', 
+    'o', 'f', ' ', 
+    's', 'e', 'q', 'u', 'e', 'n', 'c', 'e', 0
+  };
+
+  const void *z;
+  if( !db ){
+    return (void *)outOfMem;
+  }
+  if( !sqlite3SafetyCheckSickOrOk(db) ){
+    return (void *)misuse;
+  }
+  sqlite3_mutex_enter(db->mutex);
+  if( db->mallocFailed ){
+    z = (void *)outOfMem;
+  }else{
+    z = sqlite3_value_text16(db->pErr);
+    if( z==0 ){
+      sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
+      z = sqlite3_value_text16(db->pErr);
+    }
+    /* A malloc() may have failed within the call to sqlite3_value_text16()
+    ** above. If this is the case, then the db->mallocFailed flag needs to
+    ** be cleared before returning. Do this directly, instead of via
+    ** sqlite3ApiExit(), to avoid setting the database handle error message.
+    */
+    db->mallocFailed = 0;
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return z;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Return the most recent error code generated by an SQLite routine. If NULL is
+** passed to this function, we assume a malloc() failed during sqlite3_open().
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db){
+  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  if( !db || db->mallocFailed ){
+    return SQLITE_NOMEM;
+  }
+  return db->errCode & db->errMask;
+}
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db){
+  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+  if( !db || db->mallocFailed ){
+    return SQLITE_NOMEM;
+  }
+  return db->errCode;
+}
+
+/*
+** Return a string that describes the kind of error specified in the
+** argument.  For now, this simply calls the internal sqlite3ErrStr()
+** function.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int rc){
+  return sqlite3ErrStr(rc);
+}
+
+/*
+** Create a new collating function for database "db".  The name is zName
+** and the encoding is enc.
+*/
+static int createCollation(
+  sqlite3* db,
+  const char *zName, 
+  u8 enc,
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*),
+  void(*xDel)(void*)
+){
+  CollSeq *pColl;
+  int enc2;
+  
+  assert( sqlite3_mutex_held(db->mutex) );
+
+  /* If SQLITE_UTF16 is specified as the encoding type, transform this
+  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
+  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
+  */
+  enc2 = enc;
+  testcase( enc2==SQLITE_UTF16 );
+  testcase( enc2==SQLITE_UTF16_ALIGNED );
+  if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
+    enc2 = SQLITE_UTF16NATIVE;
+  }
+  if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
+    return SQLITE_MISUSE_BKPT;
+  }
+
+  /* Check if this call is removing or replacing an existing collation 
+  ** sequence. If so, and there are active VMs, return busy. If there
+  ** are no active VMs, invalidate any pre-compiled statements.
+  */
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
+  if( pColl && pColl->xCmp ){
+    if( db->nVdbeActive ){
+      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
+        "unable to delete/modify collation sequence due to active statements");
+      return SQLITE_BUSY;
+    }
+    sqlite3ExpirePreparedStatements(db);
+
+    /* If collation sequence pColl was created directly by a call to
+    ** sqlite3_create_collation, and not generated by synthCollSeq(),
+    ** then any copies made by synthCollSeq() need to be invalidated.
+    ** Also, collation destructor - CollSeq.xDel() - function may need
+    ** to be called.
+    */ 
+    if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
+      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
+      int j;
+      for(j=0; j<3; j++){
+        CollSeq *p = &aColl[j];
+        if( p->enc==pColl->enc ){
+          if( p->xDel ){
+            p->xDel(p->pUser);
+          }
+          p->xCmp = 0;
+        }
+      }
+    }
+  }
+
+  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
+  if( pColl==0 ) return SQLITE_NOMEM;
+  pColl->xCmp = xCompare;
+  pColl->pUser = pCtx;
+  pColl->xDel = xDel;
+  pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
+  sqlite3Error(db, SQLITE_OK);
+  return SQLITE_OK;
+}
+
+
+/*
+** This array defines hard upper bounds on limit values.  The
+** initializer must be kept in sync with the SQLITE_LIMIT_*
+** #defines in sqlite3.h.
+*/
+static const int aHardLimit[] = {
+  SQLITE_MAX_LENGTH,
+  SQLITE_MAX_SQL_LENGTH,
+  SQLITE_MAX_COLUMN,
+  SQLITE_MAX_EXPR_DEPTH,
+  SQLITE_MAX_COMPOUND_SELECT,
+  SQLITE_MAX_VDBE_OP,
+  SQLITE_MAX_FUNCTION_ARG,
+  SQLITE_MAX_ATTACHED,
+  SQLITE_MAX_LIKE_PATTERN_LENGTH,
+  SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
+  SQLITE_MAX_TRIGGER_DEPTH,
+  SQLITE_MAX_WORKER_THREADS,
+};
+
+/*
+** Make sure the hard limits are set to reasonable values
+*/
+#if SQLITE_MAX_LENGTH<100
+# error SQLITE_MAX_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH<100
+# error SQLITE_MAX_SQL_LENGTH must be at least 100
+#endif
+#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
+# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
+#endif
+#if SQLITE_MAX_COMPOUND_SELECT<2
+# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
+#endif
+#if SQLITE_MAX_VDBE_OP<40
+# error SQLITE_MAX_VDBE_OP must be at least 40
+#endif
+#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>1000
+# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 1000
+#endif
+#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
+# error SQLITE_MAX_ATTACHED must be between 0 and 125
+#endif
+#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
+# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
+#endif
+#if SQLITE_MAX_COLUMN>32767
+# error SQLITE_MAX_COLUMN must not exceed 32767
+#endif
+#if SQLITE_MAX_TRIGGER_DEPTH<1
+# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
+#endif
+#if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
+# error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
+#endif
+
+
+/*
+** Change the value of a limit.  Report the old value.
+** If an invalid limit index is supplied, report -1.
+** Make no changes but still report the old value if the
+** new limit is negative.
+**
+** A new lower limit does not shrink existing constructs.
+** It merely prevents new constructs that exceed the limit
+** from forming.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
+  int oldLimit;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+
+  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
+  ** there is a hard upper bound set at compile-time by a C preprocessor
+  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
+  ** "_MAX_".)
+  */
+  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
+  assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
+  assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
+  assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
+  assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
+  assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
+  assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
+                                               SQLITE_MAX_LIKE_PATTERN_LENGTH );
+  assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
+  assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
+  assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
+  assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );
+
+
+  if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
+    return -1;
+  }
+  oldLimit = db->aLimit[limitId];
+  if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
+    if( newLimit>aHardLimit[limitId] ){
+      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
+    }
+    db->aLimit[limitId] = newLimit;
+  }
+  return oldLimit;                     /* IMP: R-53341-35419 */
+}
+
+/*
+** This function is used to parse both URIs and non-URI filenames passed by the
+** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
+** URIs specified as part of ATTACH statements.
+**
+** The first argument to this function is the name of the VFS to use (or
+** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
+** query parameter. The second argument contains the URI (or non-URI filename)
+** itself. When this function is called the *pFlags variable should contain
+** the default flags to open the database handle with. The value stored in
+** *pFlags may be updated before returning if the URI filename contains 
+** "cache=xxx" or "mode=xxx" query parameters.
+**
+** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
+** the VFS that should be used to open the database file. *pzFile is set to
+** point to a buffer containing the name of the file to open. It is the 
+** responsibility of the caller to eventually call sqlite3_free() to release
+** this buffer.
+**
+** If an error occurs, then an SQLite error code is returned and *pzErrMsg
+** may be set to point to a buffer containing an English language error 
+** message. It is the responsibility of the caller to eventually release
+** this buffer by calling sqlite3_free().
+*/
+SQLITE_PRIVATE int sqlite3ParseUri(
+  const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
+  const char *zUri,               /* Nul-terminated URI to parse */
+  unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
+  sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
+  char **pzFile,                  /* OUT: Filename component of URI */
+  char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
+){
+  int rc = SQLITE_OK;
+  unsigned int flags = *pFlags;
+  const char *zVfs = zDefaultVfs;
+  char *zFile;
+  char c;
+  int nUri = sqlite3Strlen30(zUri);
+
+  assert( *pzErrMsg==0 );
+
+  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
+            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
+   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
+  ){
+    char *zOpt;
+    int eState;                   /* Parser state when parsing URI */
+    int iIn;                      /* Input character index */
+    int iOut = 0;                 /* Output character index */
+    u64 nByte = nUri+2;           /* Bytes of space to allocate */
+
+    /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
+    ** method that there may be extra parameters following the file-name.  */
+    flags |= SQLITE_OPEN_URI;
+
+    for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
+    zFile = sqlite3_malloc64(nByte);
+    if( !zFile ) return SQLITE_NOMEM;
+
+    iIn = 5;
+#ifdef SQLITE_ALLOW_URI_AUTHORITY
+    if( strncmp(zUri+5, "///", 3)==0 ){
+      iIn = 7;
+      /* The following condition causes URIs with five leading / characters
+      ** like file://///host/path to be converted into UNCs like //host/path.
+      ** The correct URI for that UNC has only two or four leading / characters
+      ** file://host/path or file:////host/path.  But 5 leading slashes is a 
+      ** common error, we are told, so we handle it as a special case. */
+      if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
+    }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
+      iIn = 16;
+    }
+#else
+    /* Discard the scheme and authority segments of the URI. */
+    if( zUri[5]=='/' && zUri[6]=='/' ){
+      iIn = 7;
+      while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
+      if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
+        *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
+            iIn-7, &zUri[7]);
+        rc = SQLITE_ERROR;
+        goto parse_uri_out;
+      }
+    }
+#endif
+
+    /* Copy the filename and any query parameters into the zFile buffer. 
+    ** Decode %HH escape codes along the way. 
+    **
+    ** Within this loop, variable eState may be set to 0, 1 or 2, depending
+    ** on the parsing context. As follows:
+    **
+    **   0: Parsing file-name.
+    **   1: Parsing name section of a name=value query parameter.
+    **   2: Parsing value section of a name=value query parameter.
+    */
+    eState = 0;
+    while( (c = zUri[iIn])!=0 && c!='#' ){
+      iIn++;
+      if( c=='%' 
+       && sqlite3Isxdigit(zUri[iIn]) 
+       && sqlite3Isxdigit(zUri[iIn+1]) 
+      ){
+        int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
+        octet += sqlite3HexToInt(zUri[iIn++]);
+
+        assert( octet>=0 && octet<256 );
+        if( octet==0 ){
+          /* This branch is taken when "%00" appears within the URI. In this
+          ** case we ignore all text in the remainder of the path, name or
+          ** value currently being parsed. So ignore the current character
+          ** and skip to the next "?", "=" or "&", as appropriate. */
+          while( (c = zUri[iIn])!=0 && c!='#' 
+              && (eState!=0 || c!='?')
+              && (eState!=1 || (c!='=' && c!='&'))
+              && (eState!=2 || c!='&')
+          ){
+            iIn++;
+          }
+          continue;
+        }
+        c = octet;
+      }else if( eState==1 && (c=='&' || c=='=') ){
+        if( zFile[iOut-1]==0 ){
+          /* An empty option name. Ignore this option altogether. */
+          while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
+          continue;
+        }
+        if( c=='&' ){
+          zFile[iOut++] = '\0';
+        }else{
+          eState = 2;
+        }
+        c = 0;
+      }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
+        c = 0;
+        eState = 1;
+      }
+      zFile[iOut++] = c;
+    }
+    if( eState==1 ) zFile[iOut++] = '\0';
+    zFile[iOut++] = '\0';
+    zFile[iOut++] = '\0';
+
+    /* Check if there were any options specified that should be interpreted 
+    ** here. Options that are interpreted here include "vfs" and those that
+    ** correspond to flags that may be passed to the sqlite3_open_v2()
+    ** method. */
+    zOpt = &zFile[sqlite3Strlen30(zFile)+1];
+    while( zOpt[0] ){
+      int nOpt = sqlite3Strlen30(zOpt);
+      char *zVal = &zOpt[nOpt+1];
+      int nVal = sqlite3Strlen30(zVal);
+
+      if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
+        zVfs = zVal;
+      }else{
+        struct OpenMode {
+          const char *z;
+          int mode;
+        } *aMode = 0;
+        char *zModeType = 0;
+        int mask = 0;
+        int limit = 0;
+
+        if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
+          static struct OpenMode aCacheMode[] = {
+            { "shared",  SQLITE_OPEN_SHAREDCACHE },
+            { "private", SQLITE_OPEN_PRIVATECACHE },
+            { 0, 0 }
+          };
+
+          mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
+          aMode = aCacheMode;
+          limit = mask;
+          zModeType = "cache";
+        }
+        if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
+          static struct OpenMode aOpenMode[] = {
+            { "ro",  SQLITE_OPEN_READONLY },
+            { "rw",  SQLITE_OPEN_READWRITE }, 
+            { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
+            { "memory", SQLITE_OPEN_MEMORY },
+            { 0, 0 }
+          };
+
+          mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
+                   | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
+          aMode = aOpenMode;
+          limit = mask & flags;
+          zModeType = "access";
+        }
+
+        if( aMode ){
+          int i;
+          int mode = 0;
+          for(i=0; aMode[i].z; i++){
+            const char *z = aMode[i].z;
+            if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
+              mode = aMode[i].mode;
+              break;
+            }
+          }
+          if( mode==0 ){
+            *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
+            rc = SQLITE_ERROR;
+            goto parse_uri_out;
+          }
+          if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
+            *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
+                                        zModeType, zVal);
+            rc = SQLITE_PERM;
+            goto parse_uri_out;
+          }
+          flags = (flags & ~mask) | mode;
+        }
+      }
+
+      zOpt = &zVal[nVal+1];
+    }
+
+  }else{
+    zFile = sqlite3_malloc64(nUri+2);
+    if( !zFile ) return SQLITE_NOMEM;
+    memcpy(zFile, zUri, nUri);
+    zFile[nUri] = '\0';
+    zFile[nUri+1] = '\0';
+    flags &= ~SQLITE_OPEN_URI;
+  }
+
+  *ppVfs = sqlite3_vfs_find(zVfs);
+  if( *ppVfs==0 ){
+    *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
+    rc = SQLITE_ERROR;
+  }
+ parse_uri_out:
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(zFile);
+    zFile = 0;
+  }
+  *pFlags = flags;
+  *pzFile = zFile;
+  return rc;
+}
+
+
+/*
+** This routine does the work of opening a database on behalf of
+** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
+** is UTF-8 encoded.
+*/
+static int openDatabase(
+  const char *zFilename, /* Database filename UTF-8 encoded */
+  sqlite3 **ppDb,        /* OUT: Returned database handle */
+  unsigned int flags,    /* Operational flags */
+  const char *zVfs       /* Name of the VFS to use */
+){
+  sqlite3 *db;                    /* Store allocated handle here */
+  int rc;                         /* Return code */
+  int isThreadsafe;               /* True for threadsafe connections */
+  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
+  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  *ppDb = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+
+  /* Only allow sensible combinations of bits in the flags argument.  
+  ** Throw an error if any non-sense combination is used.  If we
+  ** do not block illegal combinations here, it could trigger
+  ** assert() statements in deeper layers.  Sensible combinations
+  ** are:
+  **
+  **  1:  SQLITE_OPEN_READONLY
+  **  2:  SQLITE_OPEN_READWRITE
+  **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
+  */
+  assert( SQLITE_OPEN_READONLY  == 0x01 );
+  assert( SQLITE_OPEN_READWRITE == 0x02 );
+  assert( SQLITE_OPEN_CREATE    == 0x04 );
+  testcase( (1<<(flags&7))==0x02 ); /* READONLY */
+  testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
+  testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
+  if( ((1<<(flags&7)) & 0x46)==0 ){
+    return SQLITE_MISUSE_BKPT;  /* IMP: R-65497-44594 */
+  }
+
+  if( sqlite3GlobalConfig.bCoreMutex==0 ){
+    isThreadsafe = 0;
+  }else if( flags & SQLITE_OPEN_NOMUTEX ){
+    isThreadsafe = 0;
+  }else if( flags & SQLITE_OPEN_FULLMUTEX ){
+    isThreadsafe = 1;
+  }else{
+    isThreadsafe = sqlite3GlobalConfig.bFullMutex;
+  }
+  if( flags & SQLITE_OPEN_PRIVATECACHE ){
+    flags &= ~SQLITE_OPEN_SHAREDCACHE;
+  }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
+    flags |= SQLITE_OPEN_SHAREDCACHE;
+  }
+
+  /* Remove harmful bits from the flags parameter
+  **
+  ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
+  ** dealt with in the previous code block.  Besides these, the only
+  ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
+  ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
+  ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
+  ** off all other flags.
+  */
+  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
+               SQLITE_OPEN_EXCLUSIVE |
+               SQLITE_OPEN_MAIN_DB |
+               SQLITE_OPEN_TEMP_DB | 
+               SQLITE_OPEN_TRANSIENT_DB | 
+               SQLITE_OPEN_MAIN_JOURNAL | 
+               SQLITE_OPEN_TEMP_JOURNAL | 
+               SQLITE_OPEN_SUBJOURNAL | 
+               SQLITE_OPEN_MASTER_JOURNAL |
+               SQLITE_OPEN_NOMUTEX |
+               SQLITE_OPEN_FULLMUTEX |
+               SQLITE_OPEN_WAL
+             );
+
+  /* Allocate the sqlite data structure */
+  db = sqlite3MallocZero( sizeof(sqlite3) );
+  if( db==0 ) goto opendb_out;
+  if( isThreadsafe ){
+    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
+    if( db->mutex==0 ){
+      sqlite3_free(db);
+      db = 0;
+      goto opendb_out;
+    }
+  }
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = 0xff;
+  db->nDb = 2;
+  db->magic = SQLITE_MAGIC_BUSY;
+  db->aDb = db->aDbStatic;
+
+  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
+  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
+  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
+  db->autoCommit = 1;
+  db->nextAutovac = -1;
+  db->szMmap = sqlite3GlobalConfig.szMmap;
+  db->nextPagesize = 0;
+  db->nMaxSorterMmap = 0x7FFFFFFF;
+  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
+#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
+                 | SQLITE_AutoIndex
+#endif
+#if SQLITE_DEFAULT_CKPTFULLFSYNC
+                 | SQLITE_CkptFullFSync
+#endif
+#if SQLITE_DEFAULT_FILE_FORMAT<4
+                 | SQLITE_LegacyFileFmt
+#endif
+#ifdef SQLITE_ENABLE_LOAD_EXTENSION
+                 | SQLITE_LoadExtension
+#endif
+#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
+                 | SQLITE_RecTriggers
+#endif
+#if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
+                 | SQLITE_ForeignKeys
+#endif
+#if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
+                 | SQLITE_ReverseOrder
+#endif
+#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
+                 | SQLITE_CellSizeCk
+#endif
+      ;
+  sqlite3HashInit(&db->aCollSeq);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+  sqlite3HashInit(&db->aModule);
+#endif
+
+  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
+  ** and UTF-16, so add a version for each to avoid any unnecessary
+  ** conversions. The only error that can occur here is a malloc() failure.
+  **
+  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
+  ** functions:
+  */
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
+  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
+  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
+  createCollation(db, "RTRIM", SQLITE_UTF8, (void*)1, binCollFunc, 0);
+  if( db->mallocFailed ){
+    goto opendb_out;
+  }
+  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
+  ** strings is BINARY. 
+  */
+  db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, sqlite3StrBINARY, 0);
+  assert( db->pDfltColl!=0 );
+
+  /* Parse the filename/URI argument. */
+  db->openFlags = flags;
+  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
+    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
+    sqlite3_free(zErrMsg);
+    goto opendb_out;
+  }
+
+  /* Open the backend database driver */
+  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
+                        flags | SQLITE_OPEN_MAIN_DB);
+  if( rc!=SQLITE_OK ){
+    if( rc==SQLITE_IOERR_NOMEM ){
+      rc = SQLITE_NOMEM;
+    }
+    sqlite3Error(db, rc);
+    goto opendb_out;
+  }
+  sqlite3BtreeEnter(db->aDb[0].pBt);
+  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
+  if( !db->mallocFailed ) ENC(db) = SCHEMA_ENC(db);
+  sqlite3BtreeLeave(db->aDb[0].pBt);
+  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);
+
+  /* The default safety_level for the main database is 'full'; for the temp
+  ** database it is 'NONE'. This matches the pager layer defaults.  
+  */
+  db->aDb[0].zName = "main";
+  db->aDb[0].safety_level = 3;
+  db->aDb[1].zName = "temp";
+  db->aDb[1].safety_level = 1;
+
+  db->magic = SQLITE_MAGIC_OPEN;
+  if( db->mallocFailed ){
+    goto opendb_out;
+  }
+
+  /* Register all built-in functions, but do not attempt to read the
+  ** database schema yet. This is delayed until the first time the database
+  ** is accessed.
+  */
+  sqlite3Error(db, SQLITE_OK);
+  sqlite3RegisterBuiltinFunctions(db);
+
+  /* Load automatic extensions - extensions that have been registered
+  ** using the sqlite3_automatic_extension() API.
+  */
+  rc = sqlite3_errcode(db);
+  if( rc==SQLITE_OK ){
+    sqlite3AutoLoadExtensions(db);
+    rc = sqlite3_errcode(db);
+    if( rc!=SQLITE_OK ){
+      goto opendb_out;
+    }
+  }
+
+#ifdef SQLITE_ENABLE_FTS1
+  if( !db->mallocFailed ){
+    extern int sqlite3Fts1Init(sqlite3*);
+    rc = sqlite3Fts1Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS2
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    extern int sqlite3Fts2Init(sqlite3*);
+    rc = sqlite3Fts2Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS3 /* automatically defined by SQLITE_ENABLE_FTS4 */
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts3Init(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_FTS5
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3Fts5Init(db);
+  }
+#endif
+
+#ifdef DEFAULT_ENABLE_RECOVER
+  /* Initialize recover virtual table for testing. */
+  extern int recoverVtableInit(sqlite3 *db);
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = recoverVtableInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+  if( !db->mallocFailed && rc==SQLITE_OK ){
+    rc = sqlite3IcuInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_RTREE
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3RtreeInit(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_DBSTAT_VTAB
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3DbstatRegister(db);
+  }
+#endif
+
+#ifdef SQLITE_ENABLE_JSON1
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3Json1Init(db);
+  }
+#endif
+
+  /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
+  ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
+  ** mode.  Doing nothing at all also makes NORMAL the default.
+  */
+#ifdef SQLITE_DEFAULT_LOCKING_MODE
+  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
+  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
+                          SQLITE_DEFAULT_LOCKING_MODE);
+#endif
+
+  if( rc ) sqlite3Error(db, rc);
+
+  /* Enable the lookaside-malloc subsystem */
+  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
+                        sqlite3GlobalConfig.nLookaside);
+
+  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);
+
+opendb_out:
+  if( db ){
+    assert( db->mutex!=0 || isThreadsafe==0
+           || sqlite3GlobalConfig.bFullMutex==0 );
+    sqlite3_mutex_leave(db->mutex);
+  }
+  rc = sqlite3_errcode(db);
+  assert( db!=0 || rc==SQLITE_NOMEM );
+  if( rc==SQLITE_NOMEM ){
+    sqlite3_close(db);
+    db = 0;
+  }else if( rc!=SQLITE_OK ){
+    db->magic = SQLITE_MAGIC_SICK;
+  }
+  *ppDb = db;
+#ifdef SQLITE_ENABLE_SQLLOG
+  if( sqlite3GlobalConfig.xSqllog ){
+    /* Opening a db handle. Fourth parameter is passed 0. */
+    void *pArg = sqlite3GlobalConfig.pSqllogArg;
+    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
+  }
+#endif
+#if defined(SQLITE_HAS_CODEC)
+  if( rc==SQLITE_OK ){
+    const char *zHexKey = sqlite3_uri_parameter(zOpen, "hexkey");
+    if( zHexKey && zHexKey[0] ){
+      u8 iByte;
+      int i;
+      char zKey[40];
+      for(i=0, iByte=0; i<sizeof(zKey)*2 && sqlite3Isxdigit(zHexKey[i]); i++){
+        iByte = (iByte<<4) + sqlite3HexToInt(zHexKey[i]);
+        if( (i&1)!=0 ) zKey[i/2] = iByte;
+      }
+      sqlite3_key_v2(db, 0, zKey, i/2);
+    }
+  }
+#endif
+  sqlite3_free(zOpen);
+  return rc & 0xff;
+}
+
+/*
+** Open a new database handle.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_open(
+  const char *zFilename, 
+  sqlite3 **ppDb 
+){
+  return openDatabase(zFilename, ppDb,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
+}
+SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
+  const char *filename,   /* Database filename (UTF-8) */
+  sqlite3 **ppDb,         /* OUT: SQLite db handle */
+  int flags,              /* Flags */
+  const char *zVfs        /* Name of VFS module to use */
+){
+  return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Open a new database handle.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_open16(
+  const void *zFilename, 
+  sqlite3 **ppDb
+){
+  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
+  sqlite3_value *pVal;
+  int rc;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  *ppDb = 0;
+#ifndef SQLITE_OMIT_AUTOINIT
+  rc = sqlite3_initialize();
+  if( rc ) return rc;
+#endif
+  if( zFilename==0 ) zFilename = "\000\000";
+  pVal = sqlite3ValueNew(0);
+  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
+  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
+  if( zFilename8 ){
+    rc = openDatabase(zFilename8, ppDb,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
+    assert( *ppDb || rc==SQLITE_NOMEM );
+    if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
+      SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
+    }
+  }else{
+    rc = SQLITE_NOMEM;
+  }
+  sqlite3ValueFree(pVal);
+
+  return rc & 0xff;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Register a new collation sequence with the database handle db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
+  sqlite3* db, 
+  const char *zName, 
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*)
+){
+  return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
+}
+
+/*
+** Register a new collation sequence with the database handle db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
+  sqlite3* db, 
+  const char *zName, 
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*),
+  void(*xDel)(void*)
+){
+  int rc;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a new collation sequence with the database handle db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
+  sqlite3* db, 
+  const void *zName,
+  int enc, 
+  void* pCtx,
+  int(*xCompare)(void*,int,const void*,int,const void*)
+){
+  int rc = SQLITE_OK;
+  char *zName8;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  assert( !db->mallocFailed );
+  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
+  if( zName8 ){
+    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
+    sqlite3DbFree(db, zName8);
+  }
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = xCollNeeded;
+  db->xCollNeeded16 = 0;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+#ifndef SQLITE_OMIT_UTF16
+/*
+** Register a collation sequence factory callback with the database handle
+** db. Replace any previously installed collation sequence factory.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
+  sqlite3 *db, 
+  void *pCollNeededArg, 
+  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
+){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->xCollNeeded = 0;
+  db->xCollNeeded16 = xCollNeeded16;
+  db->pCollNeededArg = pCollNeededArg;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+#endif /* SQLITE_OMIT_UTF16 */
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/*
+** This function is now an anachronism. It used to be used to recover from a
+** malloc() failure, but SQLite now does this automatically.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_global_recover(void){
+  return SQLITE_OK;
+}
+#endif
+
+/*
+** Test to see whether or not the database connection is in autocommit
+** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
+** by default.  Autocommit is disabled by a BEGIN statement and reenabled
+** by the next COMMIT or ROLLBACK.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3 *db){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  return db->autoCommit;
+}
+
+/*
+** The following routines are substitutes for constants SQLITE_CORRUPT,
+** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_IOERR and possibly other error
+** constants.  They serve two purposes:
+**
+**   1.  Serve as a convenient place to set a breakpoint in a debugger
+**       to detect when version error conditions occurs.
+**
+**   2.  Invoke sqlite3_log() to provide the source code location where
+**       a low-level error is first detected.
+*/
+SQLITE_PRIVATE int sqlite3CorruptError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  sqlite3_log(SQLITE_CORRUPT,
+              "database corruption at line %d of [%.10s]",
+              lineno, 20+sqlite3_sourceid());
+  return SQLITE_CORRUPT;
+}
+SQLITE_PRIVATE int sqlite3MisuseError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  sqlite3_log(SQLITE_MISUSE, 
+              "misuse at line %d of [%.10s]",
+              lineno, 20+sqlite3_sourceid());
+  return SQLITE_MISUSE;
+}
+SQLITE_PRIVATE int sqlite3CantopenError(int lineno){
+  testcase( sqlite3GlobalConfig.xLog!=0 );
+  sqlite3_log(SQLITE_CANTOPEN, 
+              "cannot open file at line %d of [%.10s]",
+              lineno, 20+sqlite3_sourceid());
+  return SQLITE_CANTOPEN;
+}
+
+
+#ifndef SQLITE_OMIT_DEPRECATED
+/*
+** This is a convenience routine that makes sure that all thread-specific
+** data for this thread has been deallocated.
+**
+** SQLite no longer uses thread-specific data so this routine is now a
+** no-op.  It is retained for historical compatibility.
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_thread_cleanup(void){
+}
+#endif
+
+/*
+** Return meta information about a specific column of a database table.
+** See comment in sqlite3.h (sqlite.h.in) for details.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
+  sqlite3 *db,                /* Connection handle */
+  const char *zDbName,        /* Database name or NULL */
+  const char *zTableName,     /* Table name */
+  const char *zColumnName,    /* Column name */
+  char const **pzDataType,    /* OUTPUT: Declared data type */
+  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
+  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
+  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
+  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
+){
+  int rc;
+  char *zErrMsg = 0;
+  Table *pTab = 0;
+  Column *pCol = 0;
+  int iCol = 0;
+  char const *zDataType = 0;
+  char const *zCollSeq = 0;
+  int notnull = 0;
+  int primarykey = 0;
+  int autoinc = 0;
+
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+
+  /* Ensure the database schema has been loaded */
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  rc = sqlite3Init(db, &zErrMsg);
+  if( SQLITE_OK!=rc ){
+    goto error_out;
+  }
+
+  /* Locate the table in question */
+  pTab = sqlite3FindTable(db, zTableName, zDbName);
+  if( !pTab || pTab->pSelect ){
+    pTab = 0;
+    goto error_out;
+  }
+
+  /* Find the column for which info is requested */
+  if( zColumnName==0 ){
+    /* Query for existance of table only */
+  }else{
+    for(iCol=0; iCol<pTab->nCol; iCol++){
+      pCol = &pTab->aCol[iCol];
+      if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
+        break;
+      }
+    }
+    if( iCol==pTab->nCol ){
+      if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
+        iCol = pTab->iPKey;
+        pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
+      }else{
+        pTab = 0;
+        goto error_out;
+      }
+    }
+  }
+
+  /* The following block stores the meta information that will be returned
+  ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
+  ** and autoinc. At this point there are two possibilities:
+  ** 
+  **     1. The specified column name was rowid", "oid" or "_rowid_" 
+  **        and there is no explicitly declared IPK column. 
+  **
+  **     2. The table is not a view and the column name identified an 
+  **        explicitly declared column. Copy meta information from *pCol.
+  */ 
+  if( pCol ){
+    zDataType = pCol->zType;
+    zCollSeq = pCol->zColl;
+    notnull = pCol->notNull!=0;
+    primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
+    autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
+  }else{
+    zDataType = "INTEGER";
+    primarykey = 1;
+  }
+  if( !zCollSeq ){
+    zCollSeq = sqlite3StrBINARY;
+  }
+
+error_out:
+  sqlite3BtreeLeaveAll(db);
+
+  /* Whether the function call succeeded or failed, set the output parameters
+  ** to whatever their local counterparts contain. If an error did occur,
+  ** this has the effect of zeroing all output parameters.
+  */
+  if( pzDataType ) *pzDataType = zDataType;
+  if( pzCollSeq ) *pzCollSeq = zCollSeq;
+  if( pNotNull ) *pNotNull = notnull;
+  if( pPrimaryKey ) *pPrimaryKey = primarykey;
+  if( pAutoinc ) *pAutoinc = autoinc;
+
+  if( SQLITE_OK==rc && !pTab ){
+    sqlite3DbFree(db, zErrMsg);
+    zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
+        zColumnName);
+    rc = SQLITE_ERROR;
+  }
+  sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
+  sqlite3DbFree(db, zErrMsg);
+  rc = sqlite3ApiExit(db, rc);
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Sleep for a little while.  Return the amount of time slept.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int ms){
+  sqlite3_vfs *pVfs;
+  int rc;
+  pVfs = sqlite3_vfs_find(0);
+  if( pVfs==0 ) return 0;
+
+  /* This function works in milliseconds, but the underlying OsSleep() 
+  ** API uses microseconds. Hence the 1000's.
+  */
+  rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
+  return rc;
+}
+
+/*
+** Enable or disable the extended result codes.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3 *db, int onoff){
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  db->errMask = onoff ? 0xffffffff : 0xff;
+  sqlite3_mutex_leave(db->mutex);
+  return SQLITE_OK;
+}
+
+/*
+** Invoke the xFileControl method on a particular database.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
+  int rc = SQLITE_ERROR;
+  Btree *pBtree;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  pBtree = sqlite3DbNameToBtree(db, zDbName);
+  if( pBtree ){
+    Pager *pPager;
+    sqlite3_file *fd;
+    sqlite3BtreeEnter(pBtree);
+    pPager = sqlite3BtreePager(pBtree);
+    assert( pPager!=0 );
+    fd = sqlite3PagerFile(pPager);
+    assert( fd!=0 );
+    if( op==SQLITE_FCNTL_FILE_POINTER ){
+      *(sqlite3_file**)pArg = fd;
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_VFS_POINTER ){
+      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
+      rc = SQLITE_OK;
+    }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
+      *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
+      rc = SQLITE_OK;
+    }else if( fd->pMethods ){
+      rc = sqlite3OsFileControl(fd, op, pArg);
+    }else{
+      rc = SQLITE_NOTFOUND;
+    }
+    sqlite3BtreeLeave(pBtree);
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Interface to the testing logic.
+*/
+SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...){
+  int rc = 0;
+#ifdef SQLITE_OMIT_BUILTIN_TEST
+  UNUSED_PARAMETER(op);
+#else
+  va_list ap;
+  va_start(ap, op);
+  switch( op ){
+
+    /*
+    ** Save the current state of the PRNG.
+    */
+    case SQLITE_TESTCTRL_PRNG_SAVE: {
+      sqlite3PrngSaveState();
+      break;
+    }
+
+    /*
+    ** Restore the state of the PRNG to the last state saved using
+    ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
+    ** this verb acts like PRNG_RESET.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESTORE: {
+      sqlite3PrngRestoreState();
+      break;
+    }
+
+    /*
+    ** Reset the PRNG back to its uninitialized state.  The next call
+    ** to sqlite3_randomness() will reseed the PRNG using a single call
+    ** to the xRandomness method of the default VFS.
+    */
+    case SQLITE_TESTCTRL_PRNG_RESET: {
+      sqlite3_randomness(0,0);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BITVEC_TEST, size, program)
+    **
+    ** Run a test against a Bitvec object of size.  The program argument
+    ** is an array of integers that defines the test.  Return -1 on a
+    ** memory allocation error, 0 on success, or non-zero for an error.
+    ** See the sqlite3BitvecBuiltinTest() for additional information.
+    */
+    case SQLITE_TESTCTRL_BITVEC_TEST: {
+      int sz = va_arg(ap, int);
+      int *aProg = va_arg(ap, int*);
+      rc = sqlite3BitvecBuiltinTest(sz, aProg);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(FAULT_INSTALL, xCallback)
+    **
+    ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
+    ** if xCallback is not NULL.
+    **
+    ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
+    ** is called immediately after installing the new callback and the return
+    ** value from sqlite3FaultSim(0) becomes the return from
+    ** sqlite3_test_control().
+    */
+    case SQLITE_TESTCTRL_FAULT_INSTALL: {
+      /* MSVC is picky about pulling func ptrs from va lists.
+      ** http://support.microsoft.com/kb/47961
+      ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
+      */
+      typedef int(*TESTCALLBACKFUNC_t)(int);
+      sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
+      rc = sqlite3FaultSim(0);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
+    **
+    ** Register hooks to call to indicate which malloc() failures 
+    ** are benign.
+    */
+    case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
+      typedef void (*void_function)(void);
+      void_function xBenignBegin;
+      void_function xBenignEnd;
+      xBenignBegin = va_arg(ap, void_function);
+      xBenignEnd = va_arg(ap, void_function);
+      sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
+    **
+    ** Set the PENDING byte to the value in the argument, if X>0.
+    ** Make no changes if X==0.  Return the value of the pending byte
+    ** as it existing before this routine was called.
+    **
+    ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
+    ** an incompatible database file format.  Changing the PENDING byte
+    ** while any database connection is open results in undefined and
+    ** deleterious behavior.
+    */
+    case SQLITE_TESTCTRL_PENDING_BYTE: {
+      rc = PENDING_BYTE;
+#ifndef SQLITE_OMIT_WSD
+      {
+        unsigned int newVal = va_arg(ap, unsigned int);
+        if( newVal ) sqlite3PendingByte = newVal;
+      }
+#endif
+      break;
+    }
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
+    **
+    ** This action provides a run-time test to see whether or not
+    ** assert() was enabled at compile-time.  If X is true and assert()
+    ** is enabled, then the return value is true.  If X is true and
+    ** assert() is disabled, then the return value is zero.  If X is
+    ** false and assert() is enabled, then the assertion fires and the
+    ** process aborts.  If X is false and assert() is disabled, then the
+    ** return value is zero.
+    */
+    case SQLITE_TESTCTRL_ASSERT: {
+      volatile int x = 0;
+      assert( (x = va_arg(ap,int))!=0 );
+      rc = x;
+      break;
+    }
+
+
+    /*
+    **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
+    **
+    ** This action provides a run-time test to see how the ALWAYS and
+    ** NEVER macros were defined at compile-time.
+    **
+    ** The return value is ALWAYS(X).  
+    **
+    ** The recommended test is X==2.  If the return value is 2, that means
+    ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
+    ** default setting.  If the return value is 1, then ALWAYS() is either
+    ** hard-coded to true or else it asserts if its argument is false.
+    ** The first behavior (hard-coded to true) is the case if
+    ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
+    ** behavior (assert if the argument to ALWAYS() is false) is the case if
+    ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
+    **
+    ** The run-time test procedure might look something like this:
+    **
+    **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
+    **      // ALWAYS() and NEVER() are no-op pass-through macros
+    **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
+    **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
+    **    }else{
+    **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
+    **    }
+    */
+    case SQLITE_TESTCTRL_ALWAYS: {
+      int x = va_arg(ap,int);
+      rc = ALWAYS(x);
+      break;
+    }
+
+    /*
+    **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
+    **
+    ** The integer returned reveals the byte-order of the computer on which
+    ** SQLite is running:
+    **
+    **       1     big-endian,    determined at run-time
+    **      10     little-endian, determined at run-time
+    **  432101     big-endian,    determined at compile-time
+    **  123410     little-endian, determined at compile-time
+    */ 
+    case SQLITE_TESTCTRL_BYTEORDER: {
+      rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_RESERVE, sqlite3 *db, int N)
+    **
+    ** Set the nReserve size to N for the main database on the database
+    ** connection db.
+    */
+    case SQLITE_TESTCTRL_RESERVE: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      int x = va_arg(ap,int);
+      sqlite3_mutex_enter(db->mutex);
+      sqlite3BtreeSetPageSize(db->aDb[0].pBt, 0, x, 0);
+      sqlite3_mutex_leave(db->mutex);
+      break;
+    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
+    **
+    ** Enable or disable various optimizations for testing purposes.  The 
+    ** argument N is a bitmask of optimizations to be disabled.  For normal
+    ** operation N should be 0.  The idea is that a test program (like the
+    ** SQL Logic Test or SLT test module) can run the same SQL multiple times
+    ** with various optimizations disabled to verify that the same answer
+    ** is obtained in every case.
+    */
+    case SQLITE_TESTCTRL_OPTIMIZATIONS: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
+      break;
+    }
+
+#ifdef SQLITE_N_KEYWORD
+    /* sqlite3_test_control(SQLITE_TESTCTRL_ISKEYWORD, const char *zWord)
+    **
+    ** If zWord is a keyword recognized by the parser, then return the
+    ** number of keywords.  Or if zWord is not a keyword, return 0.
+    ** 
+    ** This test feature is only available in the amalgamation since
+    ** the SQLITE_N_KEYWORD macro is not defined in this file if SQLite
+    ** is built using separate source files.
+    */
+    case SQLITE_TESTCTRL_ISKEYWORD: {
+      const char *zWord = va_arg(ap, const char*);
+      int n = sqlite3Strlen30(zWord);
+      rc = (sqlite3KeywordCode((u8*)zWord, n)!=TK_ID) ? SQLITE_N_KEYWORD : 0;
+      break;
+    }
+#endif 
+
+    /* sqlite3_test_control(SQLITE_TESTCTRL_SCRATCHMALLOC, sz, &pNew, pFree);
+    **
+    ** Pass pFree into sqlite3ScratchFree(). 
+    ** If sz>0 then allocate a scratch buffer into pNew.  
+    */
+    case SQLITE_TESTCTRL_SCRATCHMALLOC: {
+      void *pFree, **ppNew;
+      int sz;
+      sz = va_arg(ap, int);
+      ppNew = va_arg(ap, void**);
+      pFree = va_arg(ap, void*);
+      if( sz ) *ppNew = sqlite3ScratchMalloc(sz);
+      sqlite3ScratchFree(pFree);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
+    **
+    ** If parameter onoff is non-zero, configure the wrappers so that all
+    ** subsequent calls to localtime() and variants fail. If onoff is zero,
+    ** undo this setting.
+    */
+    case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
+      sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
+    **
+    ** Set or clear a flag that indicates that the database file is always well-
+    ** formed and never corrupt.  This flag is clear by default, indicating that
+    ** database files might have arbitrary corruption.  Setting the flag during
+    ** testing causes certain assert() statements in the code to be activated
+    ** that demonstrat invariants on well-formed database files.
+    */
+    case SQLITE_TESTCTRL_NEVER_CORRUPT: {
+      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
+      break;
+    }
+
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
+    **
+    ** Set the VDBE coverage callback function to xCallback with context 
+    ** pointer ptr.
+    */
+    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
+#ifdef SQLITE_VDBE_COVERAGE
+      typedef void (*branch_callback)(void*,int,u8,u8);
+      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
+      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
+#endif
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
+    case SQLITE_TESTCTRL_SORTER_MMAP: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      db->nMaxSorterMmap = va_arg(ap, int);
+      break;
+    }
+
+    /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
+    **
+    ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
+    ** not.
+    */
+    case SQLITE_TESTCTRL_ISINIT: {
+      if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
+      break;
+    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
+    **
+    ** This test control is used to create imposter tables.  "db" is a pointer
+    ** to the database connection.  dbName is the database name (ex: "main" or
+    ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
+    ** or off.  "tnum" is the root page of the b-tree to which the imposter
+    ** table should connect.
+    **
+    ** Enable imposter mode only when the schema has already been parsed.  Then
+    ** run a single CREATE TABLE statement to construct the imposter table in
+    ** the parsed schema.  Then turn imposter mode back off again.
+    **
+    ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
+    ** the schema to be reparsed the next time it is needed.  This has the
+    ** effect of erasing all imposter tables.
+    */
+    case SQLITE_TESTCTRL_IMPOSTER: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      sqlite3_mutex_enter(db->mutex);
+      db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
+      db->init.busy = db->init.imposterTable = va_arg(ap,int);
+      db->init.newTnum = va_arg(ap,int);
+      if( db->init.busy==0 && db->init.newTnum>0 ){
+        sqlite3ResetAllSchemasOfConnection(db);
+      }
+      sqlite3_mutex_leave(db->mutex);
+      break;
+    }
+  }
+  va_end(ap);
+#endif /* SQLITE_OMIT_BUILTIN_TEST */
+  return rc;
+}
+
+/*
+** This is a utility routine, useful to VFS implementations, that checks
+** to see if a database file was a URI that contained a specific query 
+** parameter, and if so obtains the value of the query parameter.
+**
+** The zFilename argument is the filename pointer passed into the xOpen()
+** method of a VFS implementation.  The zParam argument is the name of the
+** query parameter we seek.  This routine returns the value of the zParam
+** parameter if it exists.  If the parameter does not exist, this routine
+** returns a NULL pointer.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam){
+  if( zFilename==0 || zParam==0 ) return 0;
+  zFilename += sqlite3Strlen30(zFilename) + 1;
+  while( zFilename[0] ){
+    int x = strcmp(zFilename, zParam);
+    zFilename += sqlite3Strlen30(zFilename) + 1;
+    if( x==0 ) return zFilename;
+    zFilename += sqlite3Strlen30(zFilename) + 1;
+  }
+  return 0;
+}
+
+/*
+** Return a boolean value for a query parameter.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  bDflt = bDflt!=0;
+  return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
+}
+
+/*
+** Return a 64-bit integer value for a query parameter.
+*/
+SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(
+  const char *zFilename,    /* Filename as passed to xOpen */
+  const char *zParam,       /* URI parameter sought */
+  sqlite3_int64 bDflt       /* return if parameter is missing */
+){
+  const char *z = sqlite3_uri_parameter(zFilename, zParam);
+  sqlite3_int64 v;
+  if( z && sqlite3DecOrHexToI64(z, &v)==SQLITE_OK ){
+    bDflt = v;
+  }
+  return bDflt;
+}
+
+/*
+** Return the Btree pointer identified by zDbName.  Return NULL if not found.
+*/
+SQLITE_PRIVATE Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
+  int i;
+  for(i=0; i<db->nDb; i++){
+    if( db->aDb[i].pBt
+     && (zDbName==0 || sqlite3StrICmp(zDbName, db->aDb[i].zName)==0)
+    ){
+      return db->aDb[i].pBt;
+    }
+  }
+  return 0;
+}
+
+/*
+** Return the filename of the database associated with a database
+** connection.
+*/
+SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return 0;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
+}
+
+/*
+** Return 1 if database is read-only or 0 if read/write.  Return -1 if
+** no such database exists.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
+  Btree *pBt;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+  pBt = sqlite3DbNameToBtree(db, zDbName);
+  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
+}
+
+#ifdef SQLITE_ENABLE_SNAPSHOT
+/*
+** Obtain a snapshot handle for the snapshot of database zDb currently 
+** being read by handle db.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_snapshot_get(
+  sqlite3 *db, 
+  const char *zDb,
+  sqlite3_snapshot **ppSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+  int iDb;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+
+  iDb = sqlite3FindDbName(db, zDb);
+  if( iDb==0 || iDb>1 ){
+    Btree *pBt = db->aDb[iDb].pBt;
+    if( 0==sqlite3BtreeIsInTrans(pBt) ){
+      rc = sqlite3BtreeBeginTrans(pBt, 0);
+      if( rc==SQLITE_OK ){
+        rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Open a read-transaction on the snapshot idendified by pSnapshot.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_snapshot_open(
+  sqlite3 *db, 
+  const char *zDb, 
+  sqlite3_snapshot *pSnapshot
+){
+  int rc = SQLITE_ERROR;
+#ifndef SQLITE_OMIT_WAL
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    return SQLITE_MISUSE_BKPT;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( db->autoCommit==0 ){
+    int iDb;
+    iDb = sqlite3FindDbName(db, zDb);
+    if( iDb==0 || iDb>1 ){
+      Btree *pBt = db->aDb[iDb].pBt;
+      if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
+        rc = sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), pSnapshot);
+        if( rc==SQLITE_OK ){
+          rc = sqlite3BtreeBeginTrans(pBt, 0);
+          sqlite3PagerSnapshotOpen(sqlite3BtreePager(pBt), 0);
+        }
+      }
+    }
+  }
+
+  sqlite3_mutex_leave(db->mutex);
+#endif   /* SQLITE_OMIT_WAL */
+  return rc;
+}
+
+/*
+** Free a snapshot handle obtained from sqlite3_snapshot_get().
+*/
+SQLITE_API void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
+  sqlite3_free(pSnapshot);
+}
+#endif /* SQLITE_ENABLE_SNAPSHOT */
+
+/************** End of main.c ************************************************/
+/************** Begin file notify.c ******************************************/
+/*
+** 2009 March 3
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the implementation of the sqlite3_unlock_notify()
+** API method and its associated functionality.
+*/
+/* #include "sqliteInt.h" */
+/* #include "btreeInt.h" */
+
+/* Omit this entire file if SQLITE_ENABLE_UNLOCK_NOTIFY is not defined. */
+#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
+
+/*
+** Public interfaces:
+**
+**   sqlite3ConnectionBlocked()
+**   sqlite3ConnectionUnlocked()
+**   sqlite3ConnectionClosed()
+**   sqlite3_unlock_notify()
+*/
+
+#define assertMutexHeld() \
+  assert( sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER)) )
+
+/*
+** Head of a linked list of all sqlite3 objects created by this process
+** for which either sqlite3.pBlockingConnection or sqlite3.pUnlockConnection
+** is not NULL. This variable may only accessed while the STATIC_MASTER
+** mutex is held.
+*/
+static sqlite3 *SQLITE_WSD sqlite3BlockedList = 0;
+
+#ifndef NDEBUG
+/*
+** This function is a complex assert() that verifies the following 
+** properties of the blocked connections list:
+**
+**   1) Each entry in the list has a non-NULL value for either 
+**      pUnlockConnection or pBlockingConnection, or both.
+**
+**   2) All entries in the list that share a common value for 
+**      xUnlockNotify are grouped together.
+**
+**   3) If the argument db is not NULL, then none of the entries in the
+**      blocked connections list have pUnlockConnection or pBlockingConnection
+**      set to db. This is used when closing connection db.
+*/
+static void checkListProperties(sqlite3 *db){
+  sqlite3 *p;
+  for(p=sqlite3BlockedList; p; p=p->pNextBlocked){
+    int seen = 0;
+    sqlite3 *p2;
+
+    /* Verify property (1) */
+    assert( p->pUnlockConnection || p->pBlockingConnection );
+
+    /* Verify property (2) */
+    for(p2=sqlite3BlockedList; p2!=p; p2=p2->pNextBlocked){
+      if( p2->xUnlockNotify==p->xUnlockNotify ) seen = 1;
+      assert( p2->xUnlockNotify==p->xUnlockNotify || !seen );
+      assert( db==0 || p->pUnlockConnection!=db );
+      assert( db==0 || p->pBlockingConnection!=db );
+    }
+  }
+}
+#else
+# define checkListProperties(x)
+#endif
+
+/*
+** Remove connection db from the blocked connections list. If connection
+** db is not currently a part of the list, this function is a no-op.
+*/
+static void removeFromBlockedList(sqlite3 *db){
+  sqlite3 **pp;
+  assertMutexHeld();
+  for(pp=&sqlite3BlockedList; *pp; pp = &(*pp)->pNextBlocked){
+    if( *pp==db ){
+      *pp = (*pp)->pNextBlocked;
+      break;
+    }
+  }
+}
+
+/*
+** Add connection db to the blocked connections list. It is assumed
+** that it is not already a part of the list.
+*/
+static void addToBlockedList(sqlite3 *db){
+  sqlite3 **pp;
+  assertMutexHeld();
+  for(
+    pp=&sqlite3BlockedList; 
+    *pp && (*pp)->xUnlockNotify!=db->xUnlockNotify; 
+    pp=&(*pp)->pNextBlocked
+  );
+  db->pNextBlocked = *pp;
+  *pp = db;
+}
+
+/*
+** Obtain the STATIC_MASTER mutex.
+*/
+static void enterMutex(void){
+  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+  checkListProperties(0);
+}
+
+/*
+** Release the STATIC_MASTER mutex.
+*/
+static void leaveMutex(void){
+  assertMutexHeld();
+  checkListProperties(0);
+  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER));
+}
+
+/*
+** Register an unlock-notify callback.
+**
+** This is called after connection "db" has attempted some operation
+** but has received an SQLITE_LOCKED error because another connection
+** (call it pOther) in the same process was busy using the same shared
+** cache.  pOther is found by looking at db->pBlockingConnection.
+**
+** If there is no blocking connection, the callback is invoked immediately,
+** before this routine returns.
+**
+** If pOther is already blocked on db, then report SQLITE_LOCKED, to indicate
+** a deadlock.
+**
+** Otherwise, make arrangements to invoke xNotify when pOther drops
+** its locks.
+**
+** Each call to this routine overrides any prior callbacks registered
+** on the same "db".  If xNotify==0 then any prior callbacks are immediately
+** cancelled.
+*/
+SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
+  sqlite3 *db,
+  void (*xNotify)(void **, int),
+  void *pArg
+){
+  int rc = SQLITE_OK;
+
+  sqlite3_mutex_enter(db->mutex);
+  enterMutex();
+
+  if( xNotify==0 ){
+    removeFromBlockedList(db);
+    db->pBlockingConnection = 0;
+    db->pUnlockConnection = 0;
+    db->xUnlockNotify = 0;
+    db->pUnlockArg = 0;
+  }else if( 0==db->pBlockingConnection ){
+    /* The blocking transaction has been concluded. Or there never was a 
+    ** blocking transaction. In either case, invoke the notify callback
+    ** immediately. 
+    */
+    xNotify(&pArg, 1);
+  }else{
+    sqlite3 *p;
+
+    for(p=db->pBlockingConnection; p && p!=db; p=p->pUnlockConnection){}
+    if( p ){
+      rc = SQLITE_LOCKED;              /* Deadlock detected. */
+    }else{
+      db->pUnlockConnection = db->pBlockingConnection;
+      db->xUnlockNotify = xNotify;
+      db->pUnlockArg = pArg;
+      removeFromBlockedList(db);
+      addToBlockedList(db);
+    }
+  }
+
+  leaveMutex();
+  assert( !db->mallocFailed );
+  sqlite3ErrorWithMsg(db, rc, (rc?"database is deadlocked":0));
+  sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** This function is called while stepping or preparing a statement 
+** associated with connection db. The operation will return SQLITE_LOCKED
+** to the user because it requires a lock that will not be available
+** until connection pBlocker concludes its current transaction.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionBlocked(sqlite3 *db, sqlite3 *pBlocker){
+  enterMutex();
+  if( db->pBlockingConnection==0 && db->pUnlockConnection==0 ){
+    addToBlockedList(db);
+  }
+  db->pBlockingConnection = pBlocker;
+  leaveMutex();
+}
+
+/*
+** This function is called when
+** the transaction opened by database db has just finished. Locks held 
+** by database connection db have been released.
+**
+** This function loops through each entry in the blocked connections
+** list and does the following:
+**
+**   1) If the sqlite3.pBlockingConnection member of a list entry is
+**      set to db, then set pBlockingConnection=0.
+**
+**   2) If the sqlite3.pUnlockConnection member of a list entry is
+**      set to db, then invoke the configured unlock-notify callback and
+**      set pUnlockConnection=0.
+**
+**   3) If the two steps above mean that pBlockingConnection==0 and
+**      pUnlockConnection==0, remove the entry from the blocked connections
+**      list.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionUnlocked(sqlite3 *db){
+  void (*xUnlockNotify)(void **, int) = 0; /* Unlock-notify cb to invoke */
+  int nArg = 0;                            /* Number of entries in aArg[] */
+  sqlite3 **pp;                            /* Iterator variable */
+  void **aArg;               /* Arguments to the unlock callback */
+  void **aDyn = 0;           /* Dynamically allocated space for aArg[] */
+  void *aStatic[16];         /* Starter space for aArg[].  No malloc required */
+
+  aArg = aStatic;
+  enterMutex();         /* Enter STATIC_MASTER mutex */
+
+  /* This loop runs once for each entry in the blocked-connections list. */
+  for(pp=&sqlite3BlockedList; *pp; /* no-op */ ){
+    sqlite3 *p = *pp;
+
+    /* Step 1. */
+    if( p->pBlockingConnection==db ){
+      p->pBlockingConnection = 0;
+    }
+
+    /* Step 2. */
+    if( p->pUnlockConnection==db ){
+      assert( p->xUnlockNotify );
+      if( p->xUnlockNotify!=xUnlockNotify && nArg!=0 ){
+        xUnlockNotify(aArg, nArg);
+        nArg = 0;
+      }
+
+      sqlite3BeginBenignMalloc();
+      assert( aArg==aDyn || (aDyn==0 && aArg==aStatic) );
+      assert( nArg<=(int)ArraySize(aStatic) || aArg==aDyn );
+      if( (!aDyn && nArg==(int)ArraySize(aStatic))
+       || (aDyn && nArg==(int)(sqlite3MallocSize(aDyn)/sizeof(void*)))
+      ){
+        /* The aArg[] array needs to grow. */
+        void **pNew = (void **)sqlite3Malloc(nArg*sizeof(void *)*2);
+        if( pNew ){
+          memcpy(pNew, aArg, nArg*sizeof(void *));
+          sqlite3_free(aDyn);
+          aDyn = aArg = pNew;
+        }else{
+          /* This occurs when the array of context pointers that need to
+          ** be passed to the unlock-notify callback is larger than the
+          ** aStatic[] array allocated on the stack and the attempt to 
+          ** allocate a larger array from the heap has failed.
+          **
+          ** This is a difficult situation to handle. Returning an error
+          ** code to the caller is insufficient, as even if an error code
+          ** is returned the transaction on connection db will still be
+          ** closed and the unlock-notify callbacks on blocked connections
+          ** will go unissued. This might cause the application to wait
+          ** indefinitely for an unlock-notify callback that will never 
+          ** arrive.
+          **
+          ** Instead, invoke the unlock-notify callback with the context
+          ** array already accumulated. We can then clear the array and
+          ** begin accumulating any further context pointers without 
+          ** requiring any dynamic allocation. This is sub-optimal because
+          ** it means that instead of one callback with a large array of
+          ** context pointers the application will receive two or more
+          ** callbacks with smaller arrays of context pointers, which will
+          ** reduce the applications ability to prioritize multiple 
+          ** connections. But it is the best that can be done under the
+          ** circumstances.
+          */
+          xUnlockNotify(aArg, nArg);
+          nArg = 0;
+        }
+      }
+      sqlite3EndBenignMalloc();
+
+      aArg[nArg++] = p->pUnlockArg;
+      xUnlockNotify = p->xUnlockNotify;
+      p->pUnlockConnection = 0;
+      p->xUnlockNotify = 0;
+      p->pUnlockArg = 0;
+    }
+
+    /* Step 3. */
+    if( p->pBlockingConnection==0 && p->pUnlockConnection==0 ){
+      /* Remove connection p from the blocked connections list. */
+      *pp = p->pNextBlocked;
+      p->pNextBlocked = 0;
+    }else{
+      pp = &p->pNextBlocked;
+    }
+  }
+
+  if( nArg!=0 ){
+    xUnlockNotify(aArg, nArg);
+  }
+  sqlite3_free(aDyn);
+  leaveMutex();         /* Leave STATIC_MASTER mutex */
+}
+
+/*
+** This is called when the database connection passed as an argument is 
+** being closed. The connection is removed from the blocked list.
+*/
+SQLITE_PRIVATE void sqlite3ConnectionClosed(sqlite3 *db){
+  sqlite3ConnectionUnlocked(db);
+  enterMutex();
+  removeFromBlockedList(db);
+  checkListProperties(db);
+  leaveMutex();
+}
+#endif
+
+/************** End of notify.c **********************************************/
+/************** Begin file recover.c *****************************************/
+/*
+** 2012 Jan 11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+*/
+/* TODO(shess): THIS MODULE IS STILL EXPERIMENTAL.  DO NOT USE IT. */
+/* Implements a virtual table "recover" which can be used to recover
+ * data from a corrupt table.  The table is walked manually, with
+ * corrupt items skipped.  Additionally, any errors while reading will
+ * be skipped.
+ *
+ * Given a table with this definition:
+ *
+ * CREATE TABLE Stuff (
+ *   name TEXT PRIMARY KEY,
+ *   value TEXT NOT NULL
+ * );
+ *
+ * to recover the data from teh table, you could do something like:
+ *
+ * -- Attach another database, the original is not trustworthy.
+ * ATTACH DATABASE '/tmp/db.db' AS rdb;
+ * -- Create a new version of the table.
+ * CREATE TABLE rdb.Stuff (
+ *   name TEXT PRIMARY KEY,
+ *   value TEXT NOT NULL
+ * );
+ * -- This will read the original table's data.
+ * CREATE VIRTUAL TABLE temp.recover_Stuff using recover(
+ *   main.Stuff,
+ *   name TEXT STRICT NOT NULL,  -- only real TEXT data allowed
+ *   value TEXT STRICT NOT NULL
+ * );
+ * -- Corruption means the UNIQUE constraint may no longer hold for
+ * -- Stuff, so either OR REPLACE or OR IGNORE must be used.
+ * INSERT OR REPLACE INTO rdb.Stuff (rowid, name, value )
+ *   SELECT rowid, name, value FROM temp.recover_Stuff;
+ * DROP TABLE temp.recover_Stuff;
+ * DETACH DATABASE rdb;
+ * -- Move db.db to replace original db in filesystem.
+ *
+ *
+ * Usage
+ *
+ * Given the goal of dealing with corruption, it would not be safe to
+ * create a recovery table in the database being recovered.  So
+ * recovery tables must be created in the temp database.  They are not
+ * appropriate to persist, in any case.  [As a bonus, sqlite_master
+ * tables can be recovered.  Perhaps more cute than useful, though.]
+ *
+ * The parameters are a specifier for the table to read, and a column
+ * definition for each bit of data stored in that table.  The named
+ * table must be convertable to a root page number by reading the
+ * sqlite_master table.  Bare table names are assumed to be in
+ * database 0 ("main"), other databases can be specified in db.table
+ * fashion.
+ *
+ * Column definitions are similar to BUT NOT THE SAME AS those
+ * provided to CREATE statements:
+ *  column-def: column-name [type-name [STRICT] [NOT NULL]]
+ *  type-name: (ANY|ROWID|INTEGER|FLOAT|NUMERIC|TEXT|BLOB)
+ *
+ * Only those exact type names are accepted, there is no type
+ * intuition.  The only constraints accepted are STRICT (see below)
+ * and NOT NULL.  Anything unexpected will cause the create to fail.
+ *
+ * ANY is a convenience to indicate that manifest typing is desired.
+ * It is equivalent to not specifying a type at all.  The results for
+ * such columns will have the type of the data's storage.  The exposed
+ * schema will contain no type for that column.
+ *
+ * ROWID is used for columns representing aliases to the rowid
+ * (INTEGER PRIMARY KEY, with or without AUTOINCREMENT), to make the
+ * concept explicit.  Such columns are actually stored as NULL, so
+ * they cannot be simply ignored.  The exposed schema will be INTEGER
+ * for that column.
+ *
+ * NOT NULL causes rows with a NULL in that column to be skipped.  It
+ * also adds NOT NULL to the column in the exposed schema.  If the
+ * table has ever had columns added using ALTER TABLE, then those
+ * columns implicitly contain NULL for rows which have not been
+ * updated.  [Workaround using COALESCE() in your SELECT statement.]
+ *
+ * The created table is read-only, with no indices.  Any SELECT will
+ * be a full-table scan, returning each valid row read from the
+ * storage of the backing table.  The rowid will be the rowid of the
+ * row from the backing table.  "Valid" means:
+ * - The cell metadata for the row is well-formed.  Mainly this means that
+ *   the cell header info describes a payload of the size indicated by
+ *   the cell's payload size.
+ * - The cell does not run off the page.
+ * - The cell does not overlap any other cell on the page.
+ * - The cell contains doesn't contain too many columns.
+ * - The types of the serialized data match the indicated types (see below).
+ *
+ *
+ * Type affinity versus type storage.
+ *
+ * http://www.sqlite.org/datatype3.html describes SQLite's type
+ * affinity system.  The system provides for automated coercion of
+ * types in certain cases, transparently enough that many developers
+ * do not realize that it is happening.  Importantly, it implies that
+ * the raw data stored in the database may not have the obvious type.
+ *
+ * Differences between the stored data types and the expected data
+ * types may be a signal of corruption.  This module makes some
+ * allowances for automatic coercion.  It is important to be concious
+ * of the difference between the schema exposed by the module, and the
+ * data types read from storage.  The following table describes how
+ * the module interprets things:
+ *
+ * type     schema   data                     STRICT
+ * ----     ------   ----                     ------
+ * ANY      <none>   any                      any
+ * ROWID    INTEGER  n/a                      n/a
+ * INTEGER  INTEGER  integer                  integer
+ * FLOAT    FLOAT    integer or float         float
+ * NUMERIC  NUMERIC  integer, float, or text  integer or float
+ * TEXT     TEXT     text or blob             text
+ * BLOB     BLOB     blob                     blob
+ *
+ * type is the type provided to the recover module, schema is the
+ * schema exposed by the module, data is the acceptable types of data
+ * decoded from storage, and STRICT is a modification of that.
+ *
+ * A very loose recovery system might use ANY for all columns, then
+ * use the appropriate sqlite3_column_*() calls to coerce to expected
+ * types.  This doesn't provide much protection if a page from a
+ * different table with the same column count is linked into an
+ * inappropriate btree.
+ *
+ * A very tight recovery system might use STRICT to enforce typing on
+ * all columns, preferring to skip rows which are valid at the storage
+ * level but don't contain the right types.  Note that FLOAT STRICT is
+ * almost certainly not appropriate, since integral values are
+ * transparently stored as integers, when that is more efficient.
+ *
+ * Another option is to use ANY for all columns and inspect each
+ * result manually (using sqlite3_column_*).  This should only be
+ * necessary in cases where developers have used manifest typing (test
+ * to make sure before you decide that you aren't using manifest
+ * typing!).
+ *
+ *
+ * Caveats
+ *
+ * Leaf pages not referenced by interior nodes will not be found.
+ *
+ * Leaf pages referenced from interior nodes of other tables will not
+ * be resolved.
+ *
+ * Rows referencing invalid overflow pages will be skipped.
+ *
+ * SQlite rows have a header which describes how to interpret the rest
+ * of the payload.  The header can be valid in cases where the rest of
+ * the record is actually corrupt (in the sense that the data is not
+ * the intended data).  This can especially happen WRT overflow pages,
+ * as lack of atomic updates between pages is the primary form of
+ * corruption I have seen in the wild.
+ */
+/* The implementation is via a series of cursors.  The cursor
+ * implementations follow the pattern:
+ *
+ * // Creates the cursor using various initialization info.
+ * int cursorCreate(...);
+ *
+ * // Returns 1 if there is no more data, 0 otherwise.
+ * int cursorEOF(Cursor *pCursor);
+ *
+ * // Various accessors can be used if not at EOF.
+ *
+ * // Move to the next item.
+ * int cursorNext(Cursor *pCursor);
+ *
+ * // Destroy the memory associated with the cursor.
+ * void cursorDestroy(Cursor *pCursor);
+ *
+ * References in the following are to sections at
+ * http://www.sqlite.org/fileformat2.html .
+ *
+ * RecoverLeafCursor iterates the records in a leaf table node
+ * described in section 1.5 "B-tree Pages".  When the node is
+ * exhausted, an interior cursor is used to get the next leaf node,
+ * and iteration continues there.
+ *
+ * RecoverInteriorCursor iterates the child pages in an interior table
+ * node described in section 1.5 "B-tree Pages".  When the node is
+ * exhausted, a parent interior cursor is used to get the next
+ * interior node at the same level, and iteration continues there.
+ *
+ * Together these record the path from the leaf level to the root of
+ * the tree.  Iteration happens from the leaves rather than the root
+ * both for efficiency and putting the special case at the front of
+ * the list is easier to implement.
+ *
+ * RecoverCursor uses a RecoverLeafCursor to iterate the rows of a
+ * table, returning results via the SQLite virtual table interface.
+ */
+/* TODO(shess): It might be useful to allow DEFAULT in types to
+ * specify what to do for NULL when an ALTER TABLE case comes up.
+ * Unfortunately, simply adding it to the exposed schema and using
+ * sqlite3_result_null() does not cause the default to be generate.
+ * Handling it ourselves seems hard, unfortunately.
+ */
+
+/* #include <assert.h> */
+/* #include <ctype.h> */
+/* #include <stdio.h> */
+/* #include <string.h> */
+
+/* Internal SQLite things that are used:
+ * u32, u64, i64 types.
+ * Btree, Pager, and DbPage structs.
+ * DbPage.pData, .pPager, and .pgno
+ * sqlite3 struct.
+ * sqlite3BtreePager() and sqlite3BtreeGetPageSize()
+ * sqlite3BtreeGetOptimalReserve()
+ * sqlite3PagerGet() and sqlite3PagerUnref()
+ * getVarint().
+ */
+/* #include "sqliteInt.h" */
+
+/* For debugging. */
+#if 0
+#define FNENTRY() fprintf(stderr, "In %s\n", __FUNCTION__)
+#else
+#define FNENTRY()
+#endif
+
+/* Generic constants and helper functions. */
+
+static const unsigned char kTableLeafPage = 0x0D;
+static const unsigned char kTableInteriorPage = 0x05;
+
+/* From section 1.5. */
+static const unsigned kiPageTypeOffset = 0;
+static const unsigned kiPageFreeBlockOffset = 1;
+static const unsigned kiPageCellCountOffset = 3;
+static const unsigned kiPageCellContentOffset = 5;
+static const unsigned kiPageFragmentedBytesOffset = 7;
+static const unsigned knPageLeafHeaderBytes = 8;
+/* Interior pages contain an additional field. */
+static const unsigned kiPageRightChildOffset = 8;
+static const unsigned kiPageInteriorHeaderBytes = 12;
+
+/* Accepted types are specified by a mask. */
+#define MASK_ROWID (1<<0)
+#define MASK_INTEGER (1<<1)
+#define MASK_FLOAT (1<<2)
+#define MASK_TEXT (1<<3)
+#define MASK_BLOB (1<<4)
+#define MASK_NULL (1<<5)
+
+/* Helpers to decode fixed-size fields. */
+static u32 decodeUnsigned16(const unsigned char *pData){
+  return (pData[0]<<8) + pData[1];
+}
+static u32 decodeUnsigned32(const unsigned char *pData){
+  return (decodeUnsigned16(pData)<<16) + decodeUnsigned16(pData+2);
+}
+static i64 decodeSigned(const unsigned char *pData, unsigned nBytes){
+  i64 r = (char)(*pData);
+  while( --nBytes ){
+    r <<= 8;
+    r += *(++pData);
+  }
+  return r;
+}
+/* Derived from vdbeaux.c, sqlite3VdbeSerialGet(), case 7. */
+/* TODO(shess): Determine if swapMixedEndianFloat() applies. */
+static double decodeFloat64(const unsigned char *pData){
+#if !defined(NDEBUG)
+  static const u64 t1 = ((u64)0x3ff00000)<<32;
+  static const double r1 = 1.0;
+  u64 t2 = t1;
+  assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
+#endif
+  i64 x = decodeSigned(pData, 8);
+  double d;
+  memcpy(&d, &x, sizeof(x));
+  return d;
+}
+
+/* Return true if a varint can safely be read from pData/nData. */
+/* TODO(shess): DbPage points into the middle of a buffer which
+ * contains the page data before DbPage.  So code should always be
+ * able to read a small number of varints safely.  Consider whether to
+ * trust that or not.
+ */
+static int checkVarint(const unsigned char *pData, unsigned nData){
+  unsigned i;
+
+  /* In the worst case the decoder takes all 8 bits of the 9th byte. */
+  if( nData>=9 ){
+    return 1;
+  }
+
+  /* Look for a high-bit-clear byte in what's left. */
+  for( i=0; i<nData; ++i ){
+    if( !(pData[i]&0x80) ){
+      return 1;
+    }
+  }
+
+  /* Cannot decode in the space given. */
+  return 0;
+}
+
+/* Return 1 if n varints can be read from pData/nData. */
+static int checkVarints(const unsigned char *pData, unsigned nData,
+                        unsigned n){
+  unsigned nCur = 0;   /* Byte offset within current varint. */
+  unsigned nFound = 0; /* Number of varints found. */
+  unsigned i;
+
+  /* In the worst case the decoder takes all 8 bits of the 9th byte. */
+  if( nData>=9*n ){
+    return 1;
+  }
+
+  for( i=0; nFound<n && i<nData; ++i ){
+    nCur++;
+    if( nCur==9 || !(pData[i]&0x80) ){
+      nFound++;
+      nCur = 0;
+    }
+  }
+
+  return nFound==n;
+}
+
+/* ctype and str[n]casecmp() can be affected by locale (eg, tr_TR).
+ * These versions consider only the ASCII space.
+ */
+/* TODO(shess): It may be reasonable to just remove the need for these
+ * entirely.  The module could require "TEXT STRICT NOT NULL", not
+ * "Text Strict Not Null" or whatever the developer felt like typing
+ * that day.  Handling corrupt data is a PERFECT place to be pedantic.
+ */
+static int ascii_isspace(char c){
+  /* From fts3_expr.c */
+  return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
+}
+static int ascii_isalnum(int x){
+  /* From fts3_tokenizer1.c */
+  return (x>='0' && x<='9') || (x>='A' && x<='Z') || (x>='a' && x<='z');
+}
+static int ascii_tolower(int x){
+  /* From fts3_tokenizer1.c */
+  return (x>='A' && x<='Z') ? x-'A'+'a' : x;
+}
+/* TODO(shess): Consider sqlite3_strnicmp() */
+static int ascii_strncasecmp(const char *s1, const char *s2, size_t n){
+  const unsigned char *us1 = (const unsigned char *)s1;
+  const unsigned char *us2 = (const unsigned char *)s2;
+  while( *us1 && *us2 && n && ascii_tolower(*us1)==ascii_tolower(*us2) ){
+    us1++, us2++, n--;
+  }
+  return n ? ascii_tolower(*us1)-ascii_tolower(*us2) : 0;
+}
+static int ascii_strcasecmp(const char *s1, const char *s2){
+  /* If s2 is equal through strlen(s1), will exit while() due to s1's
+   * trailing NUL, and return NUL-s2[strlen(s1)].
+   */
+  return ascii_strncasecmp(s1, s2, strlen(s1)+1);
+}
+
+/* For some reason I kept making mistakes with offset calculations. */
+static const unsigned char *PageData(DbPage *pPage, unsigned iOffset){
+  assert( iOffset<=pPage->nPageSize );
+  return (unsigned char *)pPage->pData + iOffset;
+}
+
+/* The first page in the file contains a file header in the first 100
+ * bytes.  The page's header information comes after that.  Note that
+ * the offsets in the page's header information are relative to the
+ * beginning of the page, NOT the end of the page header.
+ */
+static const unsigned char *PageHeader(DbPage *pPage){
+  if( pPage->pgno==1 ){
+    const unsigned nDatabaseHeader = 100;
+    return PageData(pPage, nDatabaseHeader);
+  }else{
+    return PageData(pPage, 0);
+  }
+}
+
+/* Helper to fetch the pager and page size for the named database. */
+static int GetPager(sqlite3 *db, const char *zName,
+                    Pager **pPager, unsigned *pnPageSize){
+  Btree *pBt = NULL;
+  int i;
+  for( i=0; i<db->nDb; ++i ){
+    if( ascii_strcasecmp(db->aDb[i].zName, zName)==0 ){
+      pBt = db->aDb[i].pBt;
+      break;
+    }
+  }
+  if( !pBt ){
+    return SQLITE_ERROR;
+  }
+
+  *pPager = sqlite3BtreePager(pBt);
+  *pnPageSize =
+      sqlite3BtreeGetPageSize(pBt) - sqlite3BtreeGetOptimalReserve(pBt);
+  return SQLITE_OK;
+}
+
+/* iSerialType is a type read from a record header.  See "2.1 Record Format".
+ */
+
+/* Storage size of iSerialType in bytes.  My interpretation of SQLite
+ * documentation is that text and blob fields can have 32-bit length.
+ * Values past 2^31-12 will need more than 32 bits to encode, which is
+ * why iSerialType is u64.
+ */
+static u32 SerialTypeLength(u64 iSerialType){
+  switch( iSerialType ){
+    case 0 : return 0;  /* NULL */
+    case 1 : return 1;  /* Various integers. */
+    case 2 : return 2;
+    case 3 : return 3;
+    case 4 : return 4;
+    case 5 : return 6;
+    case 6 : return 8;
+    case 7 : return 8;  /* 64-bit float. */
+    case 8 : return 0;  /* Constant 0. */
+    case 9 : return 0;  /* Constant 1. */
+    case 10 : case 11 : assert( !"RESERVED TYPE"); return 0;
+  }
+  return (u32)((iSerialType>>1) - 6);
+}
+
+/* True if iSerialType refers to a blob. */
+static int SerialTypeIsBlob(u64 iSerialType){
+  assert( iSerialType>=12 );
+  return (iSerialType%2)==0;
+}
+
+/* Returns true if the serialized type represented by iSerialType is
+ * compatible with the given type mask.
+ */
+static int SerialTypeIsCompatible(u64 iSerialType, unsigned char mask){
+  switch( iSerialType ){
+    case 0  : return (mask&MASK_NULL)!=0;
+    case 1  : return (mask&MASK_INTEGER)!=0;
+    case 2  : return (mask&MASK_INTEGER)!=0;
+    case 3  : return (mask&MASK_INTEGER)!=0;
+    case 4  : return (mask&MASK_INTEGER)!=0;
+    case 5  : return (mask&MASK_INTEGER)!=0;
+    case 6  : return (mask&MASK_INTEGER)!=0;
+    case 7  : return (mask&MASK_FLOAT)!=0;
+    case 8  : return (mask&MASK_INTEGER)!=0;
+    case 9  : return (mask&MASK_INTEGER)!=0;
+    case 10 : assert( !"RESERVED TYPE"); return 0;
+    case 11 : assert( !"RESERVED TYPE"); return 0;
+  }
+  return (mask&(SerialTypeIsBlob(iSerialType) ? MASK_BLOB : MASK_TEXT));
+}
+
+/* Versions of strdup() with return values appropriate for
+ * sqlite3_free().  malloc.c has sqlite3DbStrDup()/NDup(), but those
+ * need sqlite3DbFree(), which seems intrusive.
+ */
+static char *sqlite3_strndup(const char *z, unsigned n){
+  char *zNew;
+
+  if( z==NULL ){
+    return NULL;
+  }
+
+  zNew = sqlite3_malloc(n+1);
+  if( zNew!=NULL ){
+    memcpy(zNew, z, n);
+    zNew[n] = '\0';
+  }
+  return zNew;
+}
+static char *sqlite3_strdup(const char *z){
+  if( z==NULL ){
+    return NULL;
+  }
+  return sqlite3_strndup(z, strlen(z));
+}
+
+/* Fetch the page number of zTable in zDb from sqlite_master in zDb,
+ * and put it in *piRootPage.
+ */
+static int getRootPage(sqlite3 *db, const char *zDb, const char *zTable,
+                       u32 *piRootPage){
+  char *zSql;  /* SQL selecting root page of named element. */
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  if( strcmp(zTable, "sqlite_master")==0 ){
+    *piRootPage = 1;
+    return SQLITE_OK;
+  }
+
+  zSql = sqlite3_mprintf("SELECT rootpage FROM %s.sqlite_master "
+                         "WHERE type = 'table' AND tbl_name = %Q",
+                         zDb, zTable);
+  if( !zSql ){
+    return SQLITE_NOMEM;
+  }
+
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* Require a result. */
+  rc = sqlite3_step(pStmt);
+  if( rc==SQLITE_DONE ){
+    rc = SQLITE_CORRUPT;
+  }else if( rc==SQLITE_ROW ){
+    *piRootPage = sqlite3_column_int(pStmt, 0);
+
+    /* Require only one result. */
+    rc = sqlite3_step(pStmt);
+    if( rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
+    }else if( rc==SQLITE_ROW ){
+      rc = SQLITE_CORRUPT;
+    }
+  }
+  sqlite3_finalize(pStmt);
+  return rc;
+}
+
+static int getEncoding(sqlite3 *db, const char *zDb, int* piEncoding){
+  sqlite3_stmt *pStmt;
+  int rc;
+  char *zSql = sqlite3_mprintf("PRAGMA %s.encoding", zDb);
+  if( !zSql ){
+    return SQLITE_NOMEM;
+  }
+
+  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  sqlite3_free(zSql);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  /* Require a result. */
+  rc = sqlite3_step(pStmt);
+  if( rc==SQLITE_DONE ){
+    /* This case should not be possible. */
+    rc = SQLITE_CORRUPT;
+  }else if( rc==SQLITE_ROW ){
+    if( sqlite3_column_type(pStmt, 0)==SQLITE_TEXT ){
+      const char* z = (const char *)sqlite3_column_text(pStmt, 0);
+      /* These strings match the literals in pragma.c. */
+      if( !strcmp(z, "UTF-16le") ){
+        *piEncoding = SQLITE_UTF16LE;
+      }else if( !strcmp(z, "UTF-16be") ){
+        *piEncoding = SQLITE_UTF16BE;
+      }else if( !strcmp(z, "UTF-8") ){
+        *piEncoding = SQLITE_UTF8;
+      }else{
+        /* This case should not be possible. */
+        *piEncoding = SQLITE_UTF8;
+      }
+    }else{
+      /* This case should not be possible. */
+      *piEncoding = SQLITE_UTF8;
+    }
+
+    /* Require only one result. */
+    rc = sqlite3_step(pStmt);
+    if( rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
+    }else if( rc==SQLITE_ROW ){
+      /* This case should not be possible. */
+      rc = SQLITE_CORRUPT;
+    }
+  }
+  sqlite3_finalize(pStmt);
+  return rc;
+}
+
+/* Cursor for iterating interior nodes.  Interior page cells contain a
+ * child page number and a rowid.  The child page contains items left
+ * of the rowid (less than).  The rightmost page of the subtree is
+ * stored in the page header.
+ *
+ * interiorCursorDestroy - release all resources associated with the
+ *                         cursor and any parent cursors.
+ * interiorCursorCreate - create a cursor with the given parent and page.
+ * interiorCursorEOF - returns true if neither the cursor nor the
+ *                     parent cursors can return any more data.
+ * interiorCursorNextPage - fetch the next child page from the cursor.
+ *
+ * Logically, interiorCursorNextPage() returns the next child page
+ * number from the page the cursor is currently reading, calling the
+ * parent cursor as necessary to get new pages to read, until done.
+ * SQLITE_ROW if a page is returned, SQLITE_DONE if out of pages,
+ * error otherwise.  Unfortunately, if the table is corrupted
+ * unexpected pages can be returned.  If any unexpected page is found,
+ * leaf or otherwise, it is returned to the caller for processing,
+ * with the interior cursor left empty.  The next call to
+ * interiorCursorNextPage() will recurse to the parent cursor until an
+ * interior page to iterate is returned.
+ *
+ * Note that while interiorCursorNextPage() will refuse to follow
+ * loops, it does not keep track of pages returned for purposes of
+ * preventing duplication.
+ *
+ * Note that interiorCursorEOF() could return false (not at EOF), and
+ * interiorCursorNextPage() could still return SQLITE_DONE.  This
+ * could happen if there are more cells to iterate in an interior
+ * page, but those cells refer to invalid pages.
+ */
+typedef struct RecoverInteriorCursor RecoverInteriorCursor;
+struct RecoverInteriorCursor {
+  RecoverInteriorCursor *pParent; /* Parent node to this node. */
+  DbPage *pPage;                  /* Reference to leaf page. */
+  unsigned nPageSize;             /* Size of page. */
+  unsigned nChildren;             /* Number of children on the page. */
+  unsigned iChild;                /* Index of next child to return. */
+};
+
+static void interiorCursorDestroy(RecoverInteriorCursor *pCursor){
+  /* Destroy all the cursors to the root. */
+  while( pCursor ){
+    RecoverInteriorCursor *p = pCursor;
+    pCursor = pCursor->pParent;
+
+    if( p->pPage ){
+      sqlite3PagerUnref(p->pPage);
+      p->pPage = NULL;
+    }
+
+    memset(p, 0xA5, sizeof(*p));
+    sqlite3_free(p);
+  }
+}
+
+/* Internal helper.  Reset storage in preparation for iterating pPage. */
+static void interiorCursorSetPage(RecoverInteriorCursor *pCursor,
+                                  DbPage *pPage){
+  const unsigned knMinCellLength = 2 + 4 + 1;
+  unsigned nMaxChildren;
+  assert( PageHeader(pPage)[kiPageTypeOffset]==kTableInteriorPage );
+
+  if( pCursor->pPage ){
+    sqlite3PagerUnref(pCursor->pPage);
+    pCursor->pPage = NULL;
+  }
+  pCursor->pPage = pPage;
+  pCursor->iChild = 0;
+
+  /* A child for each cell, plus one in the header. */
+  pCursor->nChildren = decodeUnsigned16(PageHeader(pPage) +
+                                        kiPageCellCountOffset) + 1;
+
+  /* Each child requires a 16-bit offset from an array after the header,
+   * and each child contains a 32-bit page number and at least a varint
+   * (min size of one byte).  The final child page is in the header.  So
+   * the maximum value for nChildren is:
+   *   (nPageSize - kiPageInteriorHeaderBytes) /
+   *      (sizeof(uint16) + sizeof(uint32) + 1) + 1
+   */
+  /* TODO(shess): This count is very unlikely to be corrupted in
+   * isolation, so seeing this could signal to skip the page.  OTOH, I
+   * can't offhand think of how to get here unless this or the page-type
+   * byte is corrupted.  Could be an overflow page, but it would require
+   * a very large database.
+   */
+  nMaxChildren =
+      (pCursor->nPageSize - kiPageInteriorHeaderBytes) / knMinCellLength + 1;
+  if (pCursor->nChildren > nMaxChildren) {
+    pCursor->nChildren = nMaxChildren;
+  }
+}
+
+static int interiorCursorCreate(RecoverInteriorCursor *pParent,
+                                DbPage *pPage, int nPageSize,
+                                RecoverInteriorCursor **ppCursor){
+  RecoverInteriorCursor *pCursor =
+    sqlite3_malloc(sizeof(RecoverInteriorCursor));
+  if( !pCursor ){
+    return SQLITE_NOMEM;
+  }
+
+  memset(pCursor, 0, sizeof(*pCursor));
+  pCursor->pParent = pParent;
+  pCursor->nPageSize = nPageSize;
+  interiorCursorSetPage(pCursor, pPage);
+  *ppCursor = pCursor;
+  return SQLITE_OK;
+}
+
+/* Internal helper.  Return the child page number at iChild. */
+static unsigned interiorCursorChildPage(RecoverInteriorCursor *pCursor){
+  const unsigned char *pPageHeader;  /* Header of the current page. */
+  const unsigned char *pCellOffsets; /* Offset to page's cell offsets. */
+  unsigned iCellOffset;              /* Offset of target cell. */
+
+  assert( pCursor->iChild<pCursor->nChildren );
+
+  /* Rightmost child is in the header. */
+  pPageHeader = PageHeader(pCursor->pPage);
+  if( pCursor->iChild==pCursor->nChildren-1 ){
+    return decodeUnsigned32(pPageHeader + kiPageRightChildOffset);
+  }
+
+  /* Each cell is a 4-byte integer page number and a varint rowid
+   * which is greater than the rowid of items in that sub-tree (this
+   * module ignores ordering). The offset is from the beginning of the
+   * page, not from the page header.
+   */
+  pCellOffsets = pPageHeader + kiPageInteriorHeaderBytes;
+  iCellOffset = decodeUnsigned16(pCellOffsets + pCursor->iChild*2);
+  if( iCellOffset<=pCursor->nPageSize-4 ){
+    return decodeUnsigned32(PageData(pCursor->pPage, iCellOffset));
+  }
+
+  /* TODO(shess): Check for cell overlaps?  Cells require 4 bytes plus
+   * a varint.  Check could be identical to leaf check (or even a
+   * shared helper testing for "Cells starting in this range"?).
+   */
+
+  /* If the offset is broken, return an invalid page number. */
+  return 0;
+}
+
+static int interiorCursorEOF(RecoverInteriorCursor *pCursor){
+  /* Find a parent with remaining children.  EOF if none found. */
+  while( pCursor && pCursor->iChild>=pCursor->nChildren ){
+    pCursor = pCursor->pParent;
+  }
+  return pCursor==NULL;
+}
+
+/* Internal helper.  Used to detect if iPage would cause a loop. */
+static int interiorCursorPageInUse(RecoverInteriorCursor *pCursor,
+                                   unsigned iPage){
+  /* Find any parent using the indicated page. */
+  while( pCursor && pCursor->pPage->pgno!=iPage ){
+    pCursor = pCursor->pParent;
+  }
+  return pCursor!=NULL;
+}
+
+/* Get the next page from the interior cursor at *ppCursor.  Returns
+ * SQLITE_ROW with the page in *ppPage, or SQLITE_DONE if out of
+ * pages, or the error SQLite returned.
+ *
+ * If the tree is uneven, then when the cursor attempts to get a new
+ * interior page from the parent cursor, it may get a non-interior
+ * page.  In that case, the new page is returned, and *ppCursor is
+ * updated to point to the parent cursor (this cursor is freed).
+ */
+/* TODO(shess): I've tried to avoid recursion in most of this code,
+ * but this case is more challenging because the recursive call is in
+ * the middle of operation.  One option for converting it without
+ * adding memory management would be to retain the head pointer and
+ * use a helper to "back up" as needed.  Another option would be to
+ * reverse the list during traversal.
+ */
+static int interiorCursorNextPage(RecoverInteriorCursor **ppCursor,
+                                  DbPage **ppPage){
+  RecoverInteriorCursor *pCursor = *ppCursor;
+  while( 1 ){
+    int rc;
+    const unsigned char *pPageHeader;  /* Header of found page. */
+
+    /* Find a valid child page which isn't on the stack. */
+    while( pCursor->iChild<pCursor->nChildren ){
+      const unsigned iPage = interiorCursorChildPage(pCursor);
+      pCursor->iChild++;
+      if( interiorCursorPageInUse(pCursor, iPage) ){
+        fprintf(stderr, "Loop detected at %d\n", iPage);
+      }else{
+        int rc = sqlite3PagerGet(pCursor->pPage->pPager, iPage, ppPage, 0);
+        if( rc==SQLITE_OK ){
+          return SQLITE_ROW;
+        }
+      }
+    }
+
+    /* This page has no more children.  Get next page from parent. */
+    if( !pCursor->pParent ){
+      return SQLITE_DONE;
+    }
+    rc = interiorCursorNextPage(&pCursor->pParent, ppPage);
+    if( rc!=SQLITE_ROW ){
+      return rc;
+    }
+
+    /* If a non-interior page is received, that either means that the
+     * tree is uneven, or that a child was re-used (say as an overflow
+     * page).  Remove this cursor and let the caller handle the page.
+     */
+    pPageHeader = PageHeader(*ppPage);
+    if( pPageHeader[kiPageTypeOffset]!=kTableInteriorPage ){
+      *ppCursor = pCursor->pParent;
+      pCursor->pParent = NULL;
+      interiorCursorDestroy(pCursor);
+      return SQLITE_ROW;
+    }
+
+    /* Iterate the new page. */
+    interiorCursorSetPage(pCursor, *ppPage);
+    *ppPage = NULL;
+  }
+
+  assert(NULL);  /* NOTREACHED() */
+  return SQLITE_CORRUPT;
+}
+
+/* Large rows are spilled to overflow pages.  The row's main page
+ * stores the overflow page number after the local payload, with a
+ * linked list forward from there as necessary.  overflowMaybeCreate()
+ * and overflowGetSegment() provide an abstraction for accessing such
+ * data while centralizing the code.
+ *
+ * overflowDestroy - releases all resources associated with the structure.
+ * overflowMaybeCreate - create the overflow structure if it is needed
+ *                       to represent the given record.  See function comment.
+ * overflowGetSegment - fetch a segment from the record, accounting
+ *                      for overflow pages.  Segments which are not
+ *                      entirely contained with a page are constructed
+ *                      into a buffer which is returned.  See function comment.
+ */
+typedef struct RecoverOverflow RecoverOverflow;
+struct RecoverOverflow {
+  RecoverOverflow *pNextOverflow;
+  DbPage *pPage;
+  unsigned nPageSize;
+};
+
+static void overflowDestroy(RecoverOverflow *pOverflow){
+  while( pOverflow ){
+    RecoverOverflow *p = pOverflow;
+    pOverflow = p->pNextOverflow;
+
+    if( p->pPage ){
+      sqlite3PagerUnref(p->pPage);
+      p->pPage = NULL;
+    }
+
+    memset(p, 0xA5, sizeof(*p));
+    sqlite3_free(p);
+  }
+}
+
+/* Internal helper.  Used to detect if iPage would cause a loop. */
+static int overflowPageInUse(RecoverOverflow *pOverflow, unsigned iPage){
+  while( pOverflow && pOverflow->pPage->pgno!=iPage ){
+    pOverflow = pOverflow->pNextOverflow;
+  }
+  return pOverflow!=NULL;
+}
+
+/* Setup to access an nRecordBytes record beginning at iRecordOffset
+ * in pPage.  If nRecordBytes can be satisfied entirely from pPage,
+ * then no overflow pages are needed an *pnLocalRecordBytes is set to
+ * nRecordBytes.  Otherwise, *ppOverflow is set to the head of a list
+ * of overflow pages, and *pnLocalRecordBytes is set to the number of
+ * bytes local to pPage.
+ *
+ * overflowGetSegment() will do the right thing regardless of whether
+ * those values are set to be in-page or not.
+ */
+static int overflowMaybeCreate(DbPage *pPage, unsigned nPageSize,
+                               unsigned iRecordOffset, unsigned nRecordBytes,
+                               unsigned *pnLocalRecordBytes,
+                               RecoverOverflow **ppOverflow){
+  unsigned nLocalRecordBytes;  /* Record bytes in the leaf page. */
+  unsigned iNextPage;          /* Next page number for record data. */
+  unsigned nBytes;             /* Maximum record bytes as of current page. */
+  int rc;
+  RecoverOverflow *pFirstOverflow;  /* First in linked list of pages. */
+  RecoverOverflow *pLastOverflow;   /* End of linked list. */
+
+  /* Calculations from the "Table B-Tree Leaf Cell" part of section
+   * 1.5 of http://www.sqlite.org/fileformat2.html .  maxLocal and
+   * minLocal to match naming in btree.c.
+   */
+  const unsigned maxLocal = nPageSize - 35;
+  const unsigned minLocal = ((nPageSize-12)*32/255)-23;  /* m */
+
+  /* Always fit anything smaller than maxLocal. */
+  if( nRecordBytes<=maxLocal ){
+    *pnLocalRecordBytes = nRecordBytes;
+    *ppOverflow = NULL;
+    return SQLITE_OK;
+  }
+
+  /* Calculate the remainder after accounting for minLocal on the leaf
+   * page and what packs evenly into overflow pages.  If the remainder
+   * does not fit into maxLocal, then a partially-full overflow page
+   * will be required in any case, so store as little as possible locally.
+   */
+  nLocalRecordBytes = minLocal+((nRecordBytes-minLocal)%(nPageSize-4));
+  if( maxLocal<nLocalRecordBytes ){
+    nLocalRecordBytes = minLocal;
+  }
+
+  /* Don't read off the end of the page. */
+  if( iRecordOffset+nLocalRecordBytes+4>nPageSize ){
+    return SQLITE_CORRUPT;
+  }
+
+  /* First overflow page number is after the local bytes. */
+  iNextPage =
+      decodeUnsigned32(PageData(pPage, iRecordOffset + nLocalRecordBytes));
+  nBytes = nLocalRecordBytes;
+
+  /* While there are more pages to read, and more bytes are needed,
+   * get another page.
+   */
+  pFirstOverflow = pLastOverflow = NULL;
+  rc = SQLITE_OK;
+  while( iNextPage && nBytes<nRecordBytes ){
+    RecoverOverflow *pOverflow;  /* New overflow page for the list. */
+
+    rc = sqlite3PagerGet(pPage->pPager, iNextPage, &pPage, 0);
+    if( rc!=SQLITE_OK ){
+      break;
+    }
+
+    pOverflow = sqlite3_malloc(sizeof(RecoverOverflow));
+    if( !pOverflow ){
+      sqlite3PagerUnref(pPage);
+      rc = SQLITE_NOMEM;
+      break;
+    }
+    memset(pOverflow, 0, sizeof(*pOverflow));
+    pOverflow->pPage = pPage;
+    pOverflow->nPageSize = nPageSize;
+
+    if( !pFirstOverflow ){
+      pFirstOverflow = pOverflow;
+    }else{
+      pLastOverflow->pNextOverflow = pOverflow;
+    }
+    pLastOverflow = pOverflow;
+
+    iNextPage = decodeUnsigned32(pPage->pData);
+    nBytes += nPageSize-4;
+
+    /* Avoid loops. */
+    if( overflowPageInUse(pFirstOverflow, iNextPage) ){
+      fprintf(stderr, "Overflow loop detected at %d\n", iNextPage);
+      rc = SQLITE_CORRUPT;
+      break;
+    }
+  }
+
+  /* If there were not enough pages, or too many, things are corrupt.
+   * Not having enough pages is an obvious problem, all the data
+   * cannot be read.  Too many pages means that the contents of the
+   * row between the main page and the overflow page(s) is
+   * inconsistent (most likely one or more of the overflow pages does
+   * not really belong to this row).
+   */
+  if( rc==SQLITE_OK && (nBytes<nRecordBytes || iNextPage) ){
+    rc = SQLITE_CORRUPT;
+  }
+
+  if( rc==SQLITE_OK ){
+    *ppOverflow = pFirstOverflow;
+    *pnLocalRecordBytes = nLocalRecordBytes;
+  }else if( pFirstOverflow ){
+    overflowDestroy(pFirstOverflow);
+  }
+  return rc;
+}
+
+/* Use in concert with overflowMaybeCreate() to efficiently read parts
+ * of a potentially-overflowing record.  pPage and iRecordOffset are
+ * the values passed into overflowMaybeCreate(), nLocalRecordBytes and
+ * pOverflow are the values returned by that call.
+ *
+ * On SQLITE_OK, *ppBase points to nRequestBytes of data at
+ * iRequestOffset within the record.  If the data exists contiguously
+ * in a page, a direct pointer is returned, otherwise a buffer from
+ * sqlite3_malloc() is returned with the data.  *pbFree is set true if
+ * sqlite3_free() should be called on *ppBase.
+ */
+/* Operation of this function is subtle.  At any time, pPage is the
+ * current page, with iRecordOffset and nLocalRecordBytes being record
+ * data within pPage, and pOverflow being the overflow page after
+ * pPage.  This allows the code to handle both the initial leaf page
+ * and overflow pages consistently by adjusting the values
+ * appropriately.
+ */
+static int overflowGetSegment(DbPage *pPage, unsigned iRecordOffset,
+                              unsigned nLocalRecordBytes,
+                              RecoverOverflow *pOverflow,
+                              unsigned iRequestOffset, unsigned nRequestBytes,
+                              unsigned char **ppBase, int *pbFree){
+  unsigned nBase;         /* Amount of data currently collected. */
+  unsigned char *pBase;   /* Buffer to collect record data into. */
+
+  /* Skip to the page containing the start of the data. */
+  while( iRequestOffset>=nLocalRecordBytes && pOverflow ){
+    /* Factor out current page's contribution. */
+    iRequestOffset -= nLocalRecordBytes;
+
+    /* Move forward to the next page in the list. */
+    pPage = pOverflow->pPage;
+    iRecordOffset = 4;
+    nLocalRecordBytes = pOverflow->nPageSize - iRecordOffset;
+    pOverflow = pOverflow->pNextOverflow;
+  }
+
+  /* If the requested data is entirely within this page, return a
+   * pointer into the page.
+   */
+  if( iRequestOffset+nRequestBytes<=nLocalRecordBytes ){
+    /* TODO(shess): "assignment discards qualifiers from pointer target type"
+     * Having ppBase be const makes sense, but sqlite3_free() takes non-const.
+     */
+    *ppBase = (unsigned char *)PageData(pPage, iRecordOffset + iRequestOffset);
+    *pbFree = 0;
+    return SQLITE_OK;
+  }
+
+  /* The data range would require additional pages. */
+  if( !pOverflow ){
+    /* Should never happen, the range is outside the nRecordBytes
+     * passed to overflowMaybeCreate().
+     */
+    assert(NULL);  /* NOTREACHED */
+    return SQLITE_ERROR;
+  }
+
+  /* Get a buffer to construct into. */
+  nBase = 0;
+  pBase = sqlite3_malloc(nRequestBytes);
+  if( !pBase ){
+    return SQLITE_NOMEM;
+  }
+  while( nBase<nRequestBytes ){
+    /* Copy over data present on this page. */
+    unsigned nCopyBytes = nRequestBytes - nBase;
+    if( nLocalRecordBytes-iRequestOffset<nCopyBytes ){
+      nCopyBytes = nLocalRecordBytes - iRequestOffset;
+    }
+    memcpy(pBase + nBase, PageData(pPage, iRecordOffset + iRequestOffset),
+           nCopyBytes);
+    nBase += nCopyBytes;
+
+    if( pOverflow ){
+      /* Copy from start of record data in future pages. */
+      iRequestOffset = 0;
+
+      /* Move forward to the next page in the list.  Should match
+       * first while() loop.
+       */
+      pPage = pOverflow->pPage;
+      iRecordOffset = 4;
+      nLocalRecordBytes = pOverflow->nPageSize - iRecordOffset;
+      pOverflow = pOverflow->pNextOverflow;
+    }else if( nBase<nRequestBytes ){
+      /* Ran out of overflow pages with data left to deliver.  Not
+       * possible if the requested range fits within nRecordBytes
+       * passed to overflowMaybeCreate() when creating pOverflow.
+       */
+      assert(NULL);  /* NOTREACHED */
+      sqlite3_free(pBase);
+      return SQLITE_ERROR;
+    }
+  }
+  assert( nBase==nRequestBytes );
+  *ppBase = pBase;
+  *pbFree = 1;
+  return SQLITE_OK;
+}
+
+/* Primary structure for iterating the contents of a table.
+ *
+ * leafCursorDestroy - release all resources associated with the cursor.
+ * leafCursorCreate - create a cursor to iterate items from tree at
+ *                    the provided root page.
+ * leafCursorNextValidCell - get the cursor ready to access data from
+ *                           the next valid cell in the table.
+ * leafCursorCellRowid - get the current cell's rowid.
+ * leafCursorCellColumns - get current cell's column count.
+ * leafCursorCellColInfo - get type and data for a column in current cell.
+ *
+ * leafCursorNextValidCell skips cells which fail simple integrity
+ * checks, such as overlapping other cells, or being located at
+ * impossible offsets, or where header data doesn't correctly describe
+ * payload data.  Returns SQLITE_ROW if a valid cell is found,
+ * SQLITE_DONE if all pages in the tree were exhausted.
+ *
+ * leafCursorCellColInfo() accounts for overflow pages in the style of
+ * overflowGetSegment().
+ */
+typedef struct RecoverLeafCursor RecoverLeafCursor;
+struct RecoverLeafCursor {
+  RecoverInteriorCursor *pParent;  /* Parent node to this node. */
+  DbPage *pPage;                   /* Reference to leaf page. */
+  unsigned nPageSize;              /* Size of pPage. */
+  unsigned nCells;                 /* Number of cells in pPage. */
+  unsigned iCell;                  /* Current cell. */
+
+  /* Info parsed from data in iCell. */
+  i64 iRowid;                      /* rowid parsed. */
+  unsigned nRecordCols;            /* how many items in the record. */
+  u64 iRecordOffset;               /* offset to record data. */
+  /* TODO(shess): nRecordBytes and nRecordHeaderBytes are used in
+   * leafCursorCellColInfo() to prevent buffer overruns.
+   * leafCursorCellDecode() already verified that the cell is valid, so
+   * those checks should be redundant.
+   */
+  u64 nRecordBytes;                /* Size of record data. */
+  unsigned nLocalRecordBytes;      /* Amount of record data in-page. */
+  unsigned nRecordHeaderBytes;     /* Size of record header data. */
+  unsigned char *pRecordHeader;    /* Pointer to record header data. */
+  int bFreeRecordHeader;           /* True if record header requires free. */
+  RecoverOverflow *pOverflow;      /* Cell overflow info, if needed. */
+};
+
+/* Internal helper shared between next-page and create-cursor.  If
+ * pPage is a leaf page, it will be stored in the cursor and state
+ * initialized for reading cells.
+ *
+ * If pPage is an interior page, a new parent cursor is created and
+ * injected on the stack.  This is necessary to handle trees with
+ * uneven depth, but also is used during initial setup.
+ *
+ * If pPage is not a table page at all, it is discarded.
+ *
+ * If SQLITE_OK is returned, the caller no longer owns pPage,
+ * otherwise the caller is responsible for discarding it.
+ */
+static int leafCursorLoadPage(RecoverLeafCursor *pCursor, DbPage *pPage){
+  const unsigned char *pPageHeader;  /* Header of *pPage */
+
+  /* Release the current page. */
+  if( pCursor->pPage ){
+    sqlite3PagerUnref(pCursor->pPage);
+    pCursor->pPage = NULL;
+    pCursor->iCell = pCursor->nCells = 0;
+  }
+
+  /* If the page is an unexpected interior node, inject a new stack
+   * layer and try again from there.
+   */
+  pPageHeader = PageHeader(pPage);
+  if( pPageHeader[kiPageTypeOffset]==kTableInteriorPage ){
+    RecoverInteriorCursor *pParent;
+    int rc = interiorCursorCreate(pCursor->pParent, pPage, pCursor->nPageSize,
+                                  &pParent);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    pCursor->pParent = pParent;
+    return SQLITE_OK;
+  }
+
+  /* Not a leaf page, skip it. */
+  if( pPageHeader[kiPageTypeOffset]!=kTableLeafPage ){
+    sqlite3PagerUnref(pPage);
+    return SQLITE_OK;
+  }
+
+  /* Take ownership of the page and start decoding. */
+  pCursor->pPage = pPage;
+  pCursor->iCell = 0;
+  pCursor->nCells = decodeUnsigned16(pPageHeader + kiPageCellCountOffset);
+  return SQLITE_OK;
+}
+
+/* Get the next leaf-level page in the tree.  Returns SQLITE_ROW when
+ * a leaf page is found, SQLITE_DONE when no more leaves exist, or any
+ * error which occurred.
+ */
+static int leafCursorNextPage(RecoverLeafCursor *pCursor){
+  if( !pCursor->pParent ){
+    return SQLITE_DONE;
+  }
+
+  /* Repeatedly load the parent's next child page until a leaf is found. */
+  do {
+    DbPage *pNextPage;
+    int rc = interiorCursorNextPage(&pCursor->pParent, &pNextPage);
+    if( rc!=SQLITE_ROW ){
+      assert( rc==SQLITE_DONE );
+      return rc;
+    }
+
+    rc = leafCursorLoadPage(pCursor, pNextPage);
+    if( rc!=SQLITE_OK ){
+      sqlite3PagerUnref(pNextPage);
+      return rc;
+    }
+  } while( !pCursor->pPage );
+
+  return SQLITE_ROW;
+}
+
+static void leafCursorDestroyCellData(RecoverLeafCursor *pCursor){
+  if( pCursor->bFreeRecordHeader ){
+    sqlite3_free(pCursor->pRecordHeader);
+  }
+  pCursor->bFreeRecordHeader = 0;
+  pCursor->pRecordHeader = NULL;
+
+  if( pCursor->pOverflow ){
+    overflowDestroy(pCursor->pOverflow);
+    pCursor->pOverflow = NULL;
+  }
+}
+
+static void leafCursorDestroy(RecoverLeafCursor *pCursor){
+  leafCursorDestroyCellData(pCursor);
+
+  if( pCursor->pParent ){
+    interiorCursorDestroy(pCursor->pParent);
+    pCursor->pParent = NULL;
+  }
+
+  if( pCursor->pPage ){
+    sqlite3PagerUnref(pCursor->pPage);
+    pCursor->pPage = NULL;
+  }
+
+  memset(pCursor, 0xA5, sizeof(*pCursor));
+  sqlite3_free(pCursor);
+}
+
+/* Create a cursor to iterate the rows from the leaf pages of a table
+ * rooted at iRootPage.
+ */
+/* TODO(shess): recoverOpen() calls this to setup the cursor, and I
+ * think that recoverFilter() may make a hard assumption that the
+ * cursor returned will turn up at least one valid cell.
+ *
+ * The cases I can think of which break this assumption are:
+ * - pPage is a valid leaf page with no valid cells.
+ * - pPage is a valid interior page with no valid leaves.
+ * - pPage is a valid interior page who's leaves contain no valid cells.
+ * - pPage is not a valid leaf or interior page.
+ */
+static int leafCursorCreate(Pager *pPager, unsigned nPageSize,
+                            u32 iRootPage, RecoverLeafCursor **ppCursor){
+  DbPage *pPage;               /* Reference to page at iRootPage. */
+  RecoverLeafCursor *pCursor;  /* Leaf cursor being constructed. */
+  int rc;
+
+  /* Start out with the root page. */
+  rc = sqlite3PagerGet(pPager, iRootPage, &pPage, 0);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  pCursor = sqlite3_malloc(sizeof(RecoverLeafCursor));
+  if( !pCursor ){
+    sqlite3PagerUnref(pPage);
+    return SQLITE_NOMEM;
+  }
+  memset(pCursor, 0, sizeof(*pCursor));
+
+  pCursor->nPageSize = nPageSize;
+
+  rc = leafCursorLoadPage(pCursor, pPage);
+  if( rc!=SQLITE_OK ){
+    sqlite3PagerUnref(pPage);
+    leafCursorDestroy(pCursor);
+    return rc;
+  }
+
+  /* pPage wasn't a leaf page, find the next leaf page. */
+  if( !pCursor->pPage ){
+    rc = leafCursorNextPage(pCursor);
+    if( rc!=SQLITE_DONE && rc!=SQLITE_ROW ){
+      leafCursorDestroy(pCursor);
+      return rc;
+    }
+  }
+
+  *ppCursor = pCursor;
+  return SQLITE_OK;
+}
+
+/* Useful for setting breakpoints. */
+static int ValidateError(){
+  return SQLITE_ERROR;
+}
+
+/* Setup the cursor for reading the information from cell iCell. */
+static int leafCursorCellDecode(RecoverLeafCursor *pCursor){
+  const unsigned char *pPageHeader;  /* Header of current page. */
+  const unsigned char *pPageEnd;     /* Byte after end of current page. */
+  const unsigned char *pCellOffsets; /* Pointer to page's cell offsets. */
+  unsigned iCellOffset;              /* Offset of current cell (iCell). */
+  const unsigned char *pCell;        /* Pointer to data at iCellOffset. */
+  unsigned nCellMaxBytes;            /* Maximum local size of iCell. */
+  unsigned iEndOffset;               /* End of iCell's in-page data. */
+  u64 nRecordBytes;                  /* Expected size of cell, w/overflow. */
+  u64 iRowid;                        /* iCell's rowid (in table). */
+  unsigned nRead;                    /* Amount of cell read. */
+  unsigned nRecordHeaderRead;        /* Header data read. */
+  u64 nRecordHeaderBytes;            /* Header size expected. */
+  unsigned nRecordCols;              /* Columns read from header. */
+  u64 nRecordColBytes;               /* Bytes in payload for those columns. */
+  unsigned i;
+  int rc;
+
+  assert( pCursor->iCell<pCursor->nCells );
+
+  leafCursorDestroyCellData(pCursor);
+
+  /* Find the offset to the row. */
+  pPageHeader = PageHeader(pCursor->pPage);
+  pCellOffsets = pPageHeader + knPageLeafHeaderBytes;
+  pPageEnd = PageData(pCursor->pPage, pCursor->nPageSize);
+  if( pCellOffsets + pCursor->iCell*2 + 2 > pPageEnd ){
+    return ValidateError();
+  }
+  iCellOffset = decodeUnsigned16(pCellOffsets + pCursor->iCell*2);
+  if( iCellOffset>=pCursor->nPageSize ){
+    return ValidateError();
+  }
+
+  pCell = PageData(pCursor->pPage, iCellOffset);
+  nCellMaxBytes = pCursor->nPageSize - iCellOffset;
+
+  /* B-tree leaf cells lead with varint record size, varint rowid and
+   * varint header size.
+   */
+  /* TODO(shess): The smallest page size is 512 bytes, which has an m
+   * of 39.  Three varints need at most 27 bytes to encode.  I think.
+   */
+  if( !checkVarints(pCell, nCellMaxBytes, 3) ){
+    return ValidateError();
+  }
+
+  nRead = getVarint(pCell, &nRecordBytes);
+  assert( iCellOffset+nRead<=pCursor->nPageSize );
+  pCursor->nRecordBytes = nRecordBytes;
+
+  nRead += getVarint(pCell + nRead, &iRowid);
+  assert( iCellOffset+nRead<=pCursor->nPageSize );
+  pCursor->iRowid = (i64)iRowid;
+
+  pCursor->iRecordOffset = iCellOffset + nRead;
+
+  /* Start overflow setup here because nLocalRecordBytes is needed to
+   * check cell overlap.
+   */
+  rc = overflowMaybeCreate(pCursor->pPage, pCursor->nPageSize,
+                           pCursor->iRecordOffset, pCursor->nRecordBytes,
+                           &pCursor->nLocalRecordBytes,
+                           &pCursor->pOverflow);
+  if( rc!=SQLITE_OK ){
+    return ValidateError();
+  }
+
+  /* Check that no other cell starts within this cell. */
+  iEndOffset = pCursor->iRecordOffset + pCursor->nLocalRecordBytes;
+  for( i=0; i<pCursor->nCells && pCellOffsets + i*2 + 2 <= pPageEnd; ++i ){
+    const unsigned iOtherOffset = decodeUnsigned16(pCellOffsets + i*2);
+    if( iOtherOffset>iCellOffset && iOtherOffset<iEndOffset ){
+      return ValidateError();
+    }
+  }
+
+  nRecordHeaderRead = getVarint(pCell + nRead, &nRecordHeaderBytes);
+  assert( nRecordHeaderBytes<=nRecordBytes );
+  pCursor->nRecordHeaderBytes = nRecordHeaderBytes;
+
+  /* Large headers could overflow if pages are small. */
+  rc = overflowGetSegment(pCursor->pPage,
+                          pCursor->iRecordOffset, pCursor->nLocalRecordBytes,
+                          pCursor->pOverflow, 0, nRecordHeaderBytes,
+                          &pCursor->pRecordHeader, &pCursor->bFreeRecordHeader);
+  if( rc!=SQLITE_OK ){
+    return ValidateError();
+  }
+
+  /* Tally up the column count and size of data. */
+  nRecordCols = 0;
+  nRecordColBytes = 0;
+  while( nRecordHeaderRead<nRecordHeaderBytes ){
+    u64 iSerialType;  /* Type descriptor for current column. */
+    if( !checkVarint(pCursor->pRecordHeader + nRecordHeaderRead,
+                     nRecordHeaderBytes - nRecordHeaderRead) ){
+      return ValidateError();
+    }
+    nRecordHeaderRead += getVarint(pCursor->pRecordHeader + nRecordHeaderRead,
+                                   &iSerialType);
+    if( iSerialType==10 || iSerialType==11 ){
+      return ValidateError();
+    }
+    nRecordColBytes += SerialTypeLength(iSerialType);
+    nRecordCols++;
+  }
+  pCursor->nRecordCols = nRecordCols;
+
+  /* Parsing the header used as many bytes as expected. */
+  if( nRecordHeaderRead!=nRecordHeaderBytes ){
+    return ValidateError();
+  }
+
+  /* Calculated record is size of expected record. */
+  if( nRecordHeaderBytes+nRecordColBytes!=nRecordBytes ){
+    return ValidateError();
+  }
+
+  return SQLITE_OK;
+}
+
+static i64 leafCursorCellRowid(RecoverLeafCursor *pCursor){
+  return pCursor->iRowid;
+}
+
+static unsigned leafCursorCellColumns(RecoverLeafCursor *pCursor){
+  return pCursor->nRecordCols;
+}
+
+/* Get the column info for the cell.  Pass NULL for ppBase to prevent
+ * retrieving the data segment.  If *pbFree is true, *ppBase must be
+ * freed by the caller using sqlite3_free().
+ */
+static int leafCursorCellColInfo(RecoverLeafCursor *pCursor,
+                                 unsigned iCol, u64 *piColType,
+                                 unsigned char **ppBase, int *pbFree){
+  const unsigned char *pRecordHeader;  /* Current cell's header. */
+  u64 nRecordHeaderBytes;              /* Bytes in pRecordHeader. */
+  unsigned nRead;                      /* Bytes read from header. */
+  u64 iColEndOffset;                   /* Offset to end of column in cell. */
+  unsigned nColsSkipped;               /* Count columns as procesed. */
+  u64 iSerialType;                     /* Type descriptor for current column. */
+
+  /* Implicit NULL for columns past the end.  This case happens when
+   * rows have not been updated since an ALTER TABLE added columns.
+   * It is more convenient to address here than in callers.
+   */
+  if( iCol>=pCursor->nRecordCols ){
+    *piColType = 0;
+    if( ppBase ){
+      *ppBase = 0;
+      *pbFree = 0;
+    }
+    return SQLITE_OK;
+  }
+
+  /* Must be able to decode header size. */
+  pRecordHeader = pCursor->pRecordHeader;
+  if( !checkVarint(pRecordHeader, pCursor->nRecordHeaderBytes) ){
+    return SQLITE_CORRUPT;
+  }
+
+  /* Rather than caching the header size and how many bytes it took,
+   * decode it every time.
+   */
+  nRead = getVarint(pRecordHeader, &nRecordHeaderBytes);
+  assert( nRecordHeaderBytes==pCursor->nRecordHeaderBytes );
+
+  /* Scan forward to the indicated column.  Scans to _after_ column
+   * for later range checking.
+   */
+  /* TODO(shess): This could get expensive for very wide tables.  An
+   * array of iSerialType could be built in leafCursorCellDecode(), but
+   * the number of columns is dynamic per row, so it would add memory
+   * management complexity.  Enough info to efficiently forward
+   * iterate could be kept, if all clients forward iterate
+   * (recoverColumn() may not).
+   */
+  iColEndOffset = 0;
+  nColsSkipped = 0;
+  while( nColsSkipped<=iCol && nRead<nRecordHeaderBytes ){
+    if( !checkVarint(pRecordHeader + nRead, nRecordHeaderBytes - nRead) ){
+      return SQLITE_CORRUPT;
+    }
+    nRead += getVarint(pRecordHeader + nRead, &iSerialType);
+    iColEndOffset += SerialTypeLength(iSerialType);
+    nColsSkipped++;
+  }
+
+  /* Column's data extends past record's end. */
+  if( nRecordHeaderBytes+iColEndOffset>pCursor->nRecordBytes ){
+    return SQLITE_CORRUPT;
+  }
+
+  *piColType = iSerialType;
+  if( ppBase ){
+    const u32 nColBytes = SerialTypeLength(iSerialType);
+
+    /* Offset from start of record to beginning of column. */
+    const unsigned iColOffset = nRecordHeaderBytes+iColEndOffset-nColBytes;
+
+    return overflowGetSegment(pCursor->pPage, pCursor->iRecordOffset,
+                              pCursor->nLocalRecordBytes, pCursor->pOverflow,
+                              iColOffset, nColBytes, ppBase, pbFree);
+  }
+  return SQLITE_OK;
+}
+
+static int leafCursorNextValidCell(RecoverLeafCursor *pCursor){
+  while( 1 ){
+    int rc;
+
+    /* Move to the next cell. */
+    pCursor->iCell++;
+
+    /* No more cells, get the next leaf. */
+    if( pCursor->iCell>=pCursor->nCells ){
+      rc = leafCursorNextPage(pCursor);
+      if( rc!=SQLITE_ROW ){
+        return rc;
+      }
+      assert( pCursor->iCell==0 );
+    }
+
+    /* If the cell is valid, indicate that a row is available. */
+    rc = leafCursorCellDecode(pCursor);
+    if( rc==SQLITE_OK ){
+      return SQLITE_ROW;
+    }
+
+    /* Iterate until done or a valid row is found. */
+    /* TODO(shess): Remove debugging output. */
+    fprintf(stderr, "Skipping invalid cell\n");
+  }
+  return SQLITE_ERROR;
+}
+
+typedef struct Recover Recover;
+struct Recover {
+  sqlite3_vtab base;
+  sqlite3 *db;                /* Host database connection */
+  char *zDb;                  /* Database containing target table */
+  char *zTable;               /* Target table */
+  unsigned nCols;             /* Number of columns in target table */
+  unsigned char *pTypes;      /* Types of columns in target table */
+};
+
+/* Internal helper for deleting the module. */
+static void recoverRelease(Recover *pRecover){
+  sqlite3_free(pRecover->zDb);
+  sqlite3_free(pRecover->zTable);
+  sqlite3_free(pRecover->pTypes);
+  memset(pRecover, 0xA5, sizeof(*pRecover));
+  sqlite3_free(pRecover);
+}
+
+/* Helper function for initializing the module.  Forward-declared so
+ * recoverCreate() and recoverConnect() can see it.
+ */
+static int recoverInit(
+  sqlite3 *, void *, int, const char *const*, sqlite3_vtab **, char **
+);
+
+static int recoverCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  FNENTRY();
+  return recoverInit(db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/* This should never be called. */
+static int recoverConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  FNENTRY();
+  return recoverInit(db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/* No indices supported. */
+static int recoverBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  FNENTRY();
+  return SQLITE_OK;
+}
+
+/* Logically, this should never be called. */
+static int recoverDisconnect(sqlite3_vtab *pVtab){
+  FNENTRY();
+  recoverRelease((Recover*)pVtab);
+  return SQLITE_OK;
+}
+
+static int recoverDestroy(sqlite3_vtab *pVtab){
+  FNENTRY();
+  recoverRelease((Recover*)pVtab);
+  return SQLITE_OK;
+}
+
+typedef struct RecoverCursor RecoverCursor;
+struct RecoverCursor {
+  sqlite3_vtab_cursor base;
+  RecoverLeafCursor *pLeafCursor;
+  int iEncoding;
+  int bEOF;
+};
+
+static int recoverOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  Recover *pRecover = (Recover*)pVTab;
+  u32 iRootPage;                   /* Root page of the backing table. */
+  int iEncoding;                   /* UTF encoding for backing database. */
+  unsigned nPageSize;              /* Size of pages in backing database. */
+  Pager *pPager;                   /* Backing database pager. */
+  RecoverLeafCursor *pLeafCursor;  /* Cursor to read table's leaf pages. */
+  RecoverCursor *pCursor;          /* Cursor to read rows from leaves. */
+  int rc;
+
+  FNENTRY();
+
+  iRootPage = 0;
+  rc = getRootPage(pRecover->db, pRecover->zDb, pRecover->zTable,
+                   &iRootPage);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  iEncoding = 0;
+  rc = getEncoding(pRecover->db, pRecover->zDb, &iEncoding);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  rc = GetPager(pRecover->db, pRecover->zDb, &pPager, &nPageSize);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  rc = leafCursorCreate(pPager, nPageSize, iRootPage, &pLeafCursor);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+
+  pCursor = sqlite3_malloc(sizeof(RecoverCursor));
+  if( !pCursor ){
+    leafCursorDestroy(pLeafCursor);
+    return SQLITE_NOMEM;
+  }
+  memset(pCursor, 0, sizeof(*pCursor));
+  pCursor->base.pVtab = pVTab;
+  pCursor->pLeafCursor = pLeafCursor;
+  pCursor->iEncoding = iEncoding;
+
+  /* If no leaf pages were found, empty result set. */
+  /* TODO(shess): leafCursorNextValidCell() would return SQLITE_ROW or
+   * SQLITE_DONE to indicate whether there is further data to consider.
+   */
+  pCursor->bEOF = (pLeafCursor->pPage==NULL);
+
+  *ppCursor = (sqlite3_vtab_cursor*)pCursor;
+  return SQLITE_OK;
+}
+
+static int recoverClose(sqlite3_vtab_cursor *cur){
+  RecoverCursor *pCursor = (RecoverCursor*)cur;
+  FNENTRY();
+  if( pCursor->pLeafCursor ){
+    leafCursorDestroy(pCursor->pLeafCursor);
+    pCursor->pLeafCursor = NULL;
+  }
+  memset(pCursor, 0xA5, sizeof(*pCursor));
+  sqlite3_free(cur);
+  return SQLITE_OK;
+}
+
+/* Helpful place to set a breakpoint. */
+static int RecoverInvalidCell(){
+  return SQLITE_ERROR;
+}
+
+/* Returns SQLITE_OK if the cell has an appropriate number of columns
+ * with the appropriate types of data.
+ */
+static int recoverValidateLeafCell(Recover *pRecover, RecoverCursor *pCursor){
+  unsigned i;
+
+  /* If the row's storage has too many columns, skip it. */
+  if( leafCursorCellColumns(pCursor->pLeafCursor)>pRecover->nCols ){
+    return RecoverInvalidCell();
+  }
+
+  /* Skip rows with unexpected types. */
+  for( i=0; i<pRecover->nCols; ++i ){
+    u64 iType;  /* Storage type of column i. */
+    int rc;
+
+    /* ROWID alias. */
+    if( (pRecover->pTypes[i]&MASK_ROWID) ){
+      continue;
+    }
+
+    rc = leafCursorCellColInfo(pCursor->pLeafCursor, i, &iType, NULL, NULL);
+    assert( rc==SQLITE_OK );
+    if( rc!=SQLITE_OK || !SerialTypeIsCompatible(iType, pRecover->pTypes[i]) ){
+      return RecoverInvalidCell();
+    }
+  }
+
+  return SQLITE_OK;
+}
+
+static int recoverNext(sqlite3_vtab_cursor *pVtabCursor){
+  RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
+  Recover *pRecover = (Recover*)pCursor->base.pVtab;
+  int rc;
+
+  FNENTRY();
+
+  /* Scan forward to the next cell with valid storage, then check that
+   * the stored data matches the schema.
+   */
+  while( (rc = leafCursorNextValidCell(pCursor->pLeafCursor))==SQLITE_ROW ){
+    if( recoverValidateLeafCell(pRecover, pCursor)==SQLITE_OK ){
+      return SQLITE_OK;
+    }
+  }
+
+  if( rc==SQLITE_DONE ){
+    pCursor->bEOF = 1;
+    return SQLITE_OK;
+  }
+
+  assert( rc!=SQLITE_OK );
+  return rc;
+}
+
+static int recoverFilter(
+  sqlite3_vtab_cursor *pVtabCursor,
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
+  Recover *pRecover = (Recover*)pCursor->base.pVtab;
+  int rc;
+
+  FNENTRY();
+
+  /* There were no valid leaf pages in the table. */
+  if( pCursor->bEOF ){
+    return SQLITE_OK;
+  }
+
+  /* Load the first cell, and iterate forward if it's not valid.  If no cells at
+   * all are valid, recoverNext() sets bEOF and returns appropriately.
+   */
+  rc = leafCursorCellDecode(pCursor->pLeafCursor);
+  if( rc!=SQLITE_OK || recoverValidateLeafCell(pRecover, pCursor)!=SQLITE_OK ){
+    return recoverNext(pVtabCursor);
+  }
+
+  return SQLITE_OK;
+}
+
+static int recoverEof(sqlite3_vtab_cursor *pVtabCursor){
+  RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
+  FNENTRY();
+  return pCursor->bEOF;
+}
+
+static int recoverColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
+  RecoverCursor *pCursor = (RecoverCursor*)cur;
+  Recover *pRecover = (Recover*)pCursor->base.pVtab;
+  u64 iColType;             /* Storage type of column i. */
+  unsigned char *pColData;  /* Column i's data. */
+  int shouldFree;           /* Non-zero if pColData should be freed. */
+  int rc;
+
+  FNENTRY();
+
+  if( (unsigned)i>=pRecover->nCols ){
+    return SQLITE_ERROR;
+  }
+
+  /* ROWID alias. */
+  if( (pRecover->pTypes[i]&MASK_ROWID) ){
+    sqlite3_result_int64(ctx, leafCursorCellRowid(pCursor->pLeafCursor));
+    return SQLITE_OK;
+  }
+
+  pColData = NULL;
+  shouldFree = 0;
+  rc = leafCursorCellColInfo(pCursor->pLeafCursor, i, &iColType,
+                             &pColData, &shouldFree);
+  if( rc!=SQLITE_OK ){
+    return rc;
+  }
+  /* recoverValidateLeafCell() should guarantee that this will never
+   * occur.
+   */
+  if( !SerialTypeIsCompatible(iColType, pRecover->pTypes[i]) ){
+    if( shouldFree ){
+      sqlite3_free(pColData);
+    }
+    return SQLITE_ERROR;
+  }
+
+  switch( iColType ){
+    case 0 : sqlite3_result_null(ctx); break;
+    case 1 : sqlite3_result_int64(ctx, decodeSigned(pColData, 1)); break;
+    case 2 : sqlite3_result_int64(ctx, decodeSigned(pColData, 2)); break;
+    case 3 : sqlite3_result_int64(ctx, decodeSigned(pColData, 3)); break;
+    case 4 : sqlite3_result_int64(ctx, decodeSigned(pColData, 4)); break;
+    case 5 : sqlite3_result_int64(ctx, decodeSigned(pColData, 6)); break;
+    case 6 : sqlite3_result_int64(ctx, decodeSigned(pColData, 8)); break;
+    case 7 : sqlite3_result_double(ctx, decodeFloat64(pColData)); break;
+    case 8 : sqlite3_result_int(ctx, 0); break;
+    case 9 : sqlite3_result_int(ctx, 1); break;
+    case 10 : assert( iColType!=10 ); break;
+    case 11 : assert( iColType!=11 ); break;
+
+    default : {
+      u32 l = SerialTypeLength(iColType);
+
+      /* If pColData was already allocated, arrange to pass ownership. */
+      sqlite3_destructor_type pFn = SQLITE_TRANSIENT;
+      if( shouldFree ){
+        pFn = sqlite3_free;
+        shouldFree = 0;
+      }
+
+      if( SerialTypeIsBlob(iColType) ){
+        sqlite3_result_blob(ctx, pColData, l, pFn);
+      }else{
+        if( pCursor->iEncoding==SQLITE_UTF16LE ){
+          sqlite3_result_text16le(ctx, (const void*)pColData, l, pFn);
+        }else if( pCursor->iEncoding==SQLITE_UTF16BE ){
+          sqlite3_result_text16be(ctx, (const void*)pColData, l, pFn);
+        }else{
+          sqlite3_result_text(ctx, (const char*)pColData, l, pFn);
+        }
+      }
+    } break;
+  }
+  if( shouldFree ){
+    sqlite3_free(pColData);
+  }
+  return SQLITE_OK;
+}
+
+static int recoverRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
+  RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
+  FNENTRY();
+  *pRowid = leafCursorCellRowid(pCursor->pLeafCursor);
+  return SQLITE_OK;
+}
+
+static sqlite3_module recoverModule = {
+  0,                         /* iVersion */
+  recoverCreate,             /* xCreate - create a table */
+  recoverConnect,            /* xConnect - connect to an existing table */
+  recoverBestIndex,          /* xBestIndex - Determine search strategy */
+  recoverDisconnect,         /* xDisconnect - Disconnect from a table */
+  recoverDestroy,            /* xDestroy - Drop a table */
+  recoverOpen,               /* xOpen - open a cursor */
+  recoverClose,              /* xClose - close a cursor */
+  recoverFilter,             /* xFilter - configure scan constraints */
+  recoverNext,               /* xNext - advance a cursor */
+  recoverEof,                /* xEof */
+  recoverColumn,             /* xColumn - read data */
+  recoverRowid,              /* xRowid - read data */
+  0,                         /* xUpdate - write data */
+  0,                         /* xBegin - begin transaction */
+  0,                         /* xSync - sync transaction */
+  0,                         /* xCommit - commit transaction */
+  0,                         /* xRollback - rollback transaction */
+  0,                         /* xFindFunction - function overloading */
+  0,                         /* xRename - rename the table */
+};
+
+CHROMIUM_SQLITE_API
+int recoverVtableInit(sqlite3 *db){
+  return sqlite3_create_module_v2(db, "recover", &recoverModule, NULL, 0);
+}
+
+/* This section of code is for parsing the create input and
+ * initializing the module.
+ */
+
+/* Find the next word in zText and place the endpoints in pzWord*.
+ * Returns true if the word is non-empty.  "Word" is defined as
+ * ASCII alphanumeric plus '_' at this time.
+ */
+static int findWord(const char *zText,
+                    const char **pzWordStart, const char **pzWordEnd){
+  int r;
+  while( ascii_isspace(*zText) ){
+    zText++;
+  }
+  *pzWordStart = zText;
+  while( ascii_isalnum(*zText) || *zText=='_' ){
+    zText++;
+  }
+  r = zText>*pzWordStart;  /* In case pzWordStart==pzWordEnd */
+  *pzWordEnd = zText;
+  return r;
+}
+
+/* Return true if the next word in zText is zWord, also setting
+ * *pzContinue to the character after the word.
+ */
+static int expectWord(const char *zText, const char *zWord,
+                      const char **pzContinue){
+  const char *zWordStart, *zWordEnd;
+  if( findWord(zText, &zWordStart, &zWordEnd) &&
+      ascii_strncasecmp(zWord, zWordStart, zWordEnd - zWordStart)==0 ){
+    *pzContinue = zWordEnd;
+    return 1;
+  }
+  return 0;
+}
+
+/* Parse the name and type information out of parameter.  In case of
+ * success, *pzNameStart/End contain the name of the column,
+ * *pzTypeStart/End contain the top-level type, and *pTypeMask has the
+ * type mask to use for the column.
+ */
+static int findNameAndType(const char *parameter,
+                           const char **pzNameStart, const char **pzNameEnd,
+                           const char **pzTypeStart, const char **pzTypeEnd,
+                           unsigned char *pTypeMask){
+  unsigned nNameLen;   /* Length of found name. */
+  const char *zEnd;    /* Current end of parsed column information. */
+  int bNotNull;        /* Non-zero if NULL is not allowed for name. */
+  int bStrict;         /* Non-zero if column requires exact type match. */
+  const char *zDummy;  /* Dummy parameter, result unused. */
+  unsigned i;
+
+  /* strictMask is used for STRICT, strictMask|otherMask if STRICT is
+   * not supplied.  zReplace provides an alternate type to expose to
+   * the caller.
+   */
+  static struct {
+    const char *zName;
+    unsigned char strictMask;
+    unsigned char otherMask;
+    const char *zReplace;
+  } kTypeInfo[] = {
+    { "ANY",
+      MASK_INTEGER | MASK_FLOAT | MASK_BLOB | MASK_TEXT | MASK_NULL,
+      0, "",
+    },
+    { "ROWID",   MASK_INTEGER | MASK_ROWID,             0, "INTEGER", },
+    { "INTEGER", MASK_INTEGER | MASK_NULL,              0, NULL, },
+    { "FLOAT",   MASK_FLOAT | MASK_NULL,                MASK_INTEGER, NULL, },
+    { "NUMERIC", MASK_INTEGER | MASK_FLOAT | MASK_NULL, MASK_TEXT, NULL, },
+    { "TEXT",    MASK_TEXT | MASK_NULL,                 MASK_BLOB, NULL, },
+    { "BLOB",    MASK_BLOB | MASK_NULL,                 0, NULL, },
+  };
+
+  if( !findWord(parameter, pzNameStart, pzNameEnd) ){
+    return SQLITE_MISUSE;
+  }
+
+  /* Manifest typing, accept any storage type. */
+  if( !findWord(*pzNameEnd, pzTypeStart, pzTypeEnd) ){
+    *pzTypeEnd = *pzTypeStart = "";
+    *pTypeMask = MASK_INTEGER | MASK_FLOAT | MASK_BLOB | MASK_TEXT | MASK_NULL;
+    return SQLITE_OK;
+  }
+
+  nNameLen = *pzTypeEnd - *pzTypeStart;
+  for( i=0; i<ArraySize(kTypeInfo); ++i ){
+    if( ascii_strncasecmp(kTypeInfo[i].zName, *pzTypeStart, nNameLen)==0 ){
+      break;
+    }
+  }
+  if( i==ArraySize(kTypeInfo) ){
+    return SQLITE_MISUSE;
+  }
+
+  zEnd = *pzTypeEnd;
+  bStrict = 0;
+  if( expectWord(zEnd, "STRICT", &zEnd) ){
+    /* TODO(shess): Ick.  But I don't want another single-purpose
+     * flag, either.
+     */
+    if( kTypeInfo[i].zReplace && !kTypeInfo[i].zReplace[0] ){
+      return SQLITE_MISUSE;
+    }
+    bStrict = 1;
+  }
+
+  bNotNull = 0;
+  if( expectWord(zEnd, "NOT", &zEnd) ){
+    if( expectWord(zEnd, "NULL", &zEnd) ){
+      bNotNull = 1;
+    }else{
+      /* Anything other than NULL after NOT is an error. */
+      return SQLITE_MISUSE;
+    }
+  }
+
+  /* Anything else is an error. */
+  if( findWord(zEnd, &zDummy, &zDummy) ){
+    return SQLITE_MISUSE;
+  }
+
+  *pTypeMask = kTypeInfo[i].strictMask;
+  if( !bStrict ){
+    *pTypeMask |= kTypeInfo[i].otherMask;
+  }
+  if( bNotNull ){
+    *pTypeMask &= ~MASK_NULL;
+  }
+  if( kTypeInfo[i].zReplace ){
+    *pzTypeStart = kTypeInfo[i].zReplace;
+    *pzTypeEnd = *pzTypeStart + strlen(*pzTypeStart);
+  }
+  return SQLITE_OK;
+}
+
+/* Parse the arguments, placing type masks in *pTypes and the exposed
+ * schema in *pzCreateSql (for sqlite3_declare_vtab).
+ */
+static int ParseColumnsAndGenerateCreate(unsigned nCols,
+                                         const char *const *pCols,
+                                         char **pzCreateSql,
+                                         unsigned char *pTypes,
+                                         char **pzErr){
+  unsigned i;
+  char *zCreateSql = sqlite3_mprintf("CREATE TABLE x(");
+  if( !zCreateSql ){
+    return SQLITE_NOMEM;
+  }
+
+  for( i=0; i<nCols; i++ ){
+    const char *zSep = (i < nCols - 1 ? ", " : ")");
+    const char *zNotNull = "";
+    const char *zNameStart, *zNameEnd;
+    const char *zTypeStart, *zTypeEnd;
+    int rc = findNameAndType(pCols[i],
+                             &zNameStart, &zNameEnd,
+                             &zTypeStart, &zTypeEnd,
+                             &pTypes[i]);
+    if( rc!=SQLITE_OK ){
+      *pzErr = sqlite3_mprintf("unable to parse column %d", i);
+      sqlite3_free(zCreateSql);
+      return rc;
+    }
+
+    if( !(pTypes[i]&MASK_NULL) ){
+      zNotNull = " NOT NULL";
+    }
+
+    /* Add name and type to the create statement. */
+    zCreateSql = sqlite3_mprintf("%z%.*s %.*s%s%s",
+                                 zCreateSql,
+                                 zNameEnd - zNameStart, zNameStart,
+                                 zTypeEnd - zTypeStart, zTypeStart,
+                                 zNotNull, zSep);
+    if( !zCreateSql ){
+      return SQLITE_NOMEM;
+    }
+  }
+
+  *pzCreateSql = zCreateSql;
+  return SQLITE_OK;
+}
+
+/* Helper function for initializing the module. */
+/* argv[0] module name
+ * argv[1] db name for virtual table
+ * argv[2] virtual table name
+ * argv[3] backing table name
+ * argv[4] columns
+ */
+/* TODO(shess): Since connect isn't supported, could inline into
+ * recoverCreate().
+ */
+/* TODO(shess): Explore cases where it would make sense to set *pzErr. */
+static int recoverInit(
+  sqlite3 *db,                        /* Database connection */
+  void *pAux,                         /* unused */
+  int argc, const char *const*argv,   /* Parameters to CREATE TABLE statement */
+  sqlite3_vtab **ppVtab,              /* OUT: New virtual table */
+  char **pzErr                        /* OUT: Error message, if any */
+){
+  const int kTypeCol = 4;  /* First argument with column type info. */
+  Recover *pRecover;       /* Virtual table structure being created. */
+  char *zDot;              /* Any dot found in "db.table" backing. */
+  u32 iRootPage;           /* Root page of backing table. */
+  char *zCreateSql;        /* Schema of created virtual table. */
+  int rc;
+
+  /* Require to be in the temp database. */
+  if( ascii_strcasecmp(argv[1], "temp")!=0 ){
+    *pzErr = sqlite3_mprintf("recover table must be in temp database");
+    return SQLITE_MISUSE;
+  }
+
+  /* Need the backing table and at least one column. */
+  if( argc<=kTypeCol ){
+    *pzErr = sqlite3_mprintf("no columns specified");
+    return SQLITE_MISUSE;
+  }
+
+  pRecover = sqlite3_malloc(sizeof(Recover));
+  if( !pRecover ){
+    return SQLITE_NOMEM;
+  }
+  memset(pRecover, 0, sizeof(*pRecover));
+  pRecover->base.pModule = &recoverModule;
+  pRecover->db = db;
+
+  /* Parse out db.table, assuming main if no dot. */
+  zDot = strchr(argv[3], '.');
+  if( !zDot ){
+    pRecover->zDb = sqlite3_strdup(db->aDb[0].zName);
+    pRecover->zTable = sqlite3_strdup(argv[3]);
+  }else if( zDot>argv[3] && zDot[1]!='\0' ){
+    pRecover->zDb = sqlite3_strndup(argv[3], zDot - argv[3]);
+    pRecover->zTable = sqlite3_strdup(zDot + 1);
+  }else{
+    /* ".table" or "db." not allowed. */
+    *pzErr = sqlite3_mprintf("ill-formed table specifier");
+    recoverRelease(pRecover);
+    return SQLITE_ERROR;
+  }
+
+  pRecover->nCols = argc - kTypeCol;
+  pRecover->pTypes = sqlite3_malloc(pRecover->nCols);
+  if( !pRecover->zDb || !pRecover->zTable || !pRecover->pTypes ){
+    recoverRelease(pRecover);
+    return SQLITE_NOMEM;
+  }
+
+  /* Require the backing table to exist. */
+  /* TODO(shess): Be more pedantic about the form of the descriptor
+   * string.  This already fails for poorly-formed strings, simply
+   * because there won't be a root page, but it would make more sense
+   * to be explicit.
+   */
+  rc = getRootPage(pRecover->db, pRecover->zDb, pRecover->zTable, &iRootPage);
+  if( rc!=SQLITE_OK ){
+    *pzErr = sqlite3_mprintf("unable to find backing table");
+    recoverRelease(pRecover);
+    return rc;
+  }
+
+  /* Parse the column definitions. */
+  rc = ParseColumnsAndGenerateCreate(pRecover->nCols, argv + kTypeCol,
+                                     &zCreateSql, pRecover->pTypes, pzErr);
+  if( rc!=SQLITE_OK ){
+    recoverRelease(pRecover);
+    return rc;
+  }
+
+  rc = sqlite3_declare_vtab(db, zCreateSql);
+  sqlite3_free(zCreateSql);
+  if( rc!=SQLITE_OK ){
+    recoverRelease(pRecover);
+    return rc;
+  }
+
+  *ppVtab = (sqlite3_vtab *)pRecover;
+  return SQLITE_OK;
+}
+
+/************** End of recover.c *********************************************/
+
+/* Chain include. */ 
+#include "sqlite3.06.c"