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Unified Diff: third_party/sqlite/src/src/where.c

Issue 1610963002: Import SQLite 3.10.2. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 4 years, 11 months ago
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Index: third_party/sqlite/src/src/where.c
diff --git a/third_party/sqlite/src/src/where.c b/third_party/sqlite/src/src/where.c
index 793b01d1678edeebc90426661e82a05775a6e6a2..e86e26ef1ae8c5805e51a88a7495eb29115538d4 100644
--- a/third_party/sqlite/src/src/where.c
+++ b/third_party/sqlite/src/src/where.c
@@ -19,6 +19,15 @@
#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
*/
@@ -60,9 +69,11 @@ int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
}
/*
-** Return TRUE if an UPDATE or DELETE statement can operate directly on
-** the rowids returned by a WHERE clause. Return FALSE if doing an
-** UPDATE or DELETE might change subsequent WHERE clause results.
+** 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
@@ -76,7 +87,14 @@ int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
*/
int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
- return pWInfo->okOnePass;
+#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;
}
/*
@@ -128,152 +146,10 @@ whereOrInsert_done:
}
/*
-** Initialize a preallocated WhereClause structure.
-*/
-static void whereClauseInit(
- 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;
-}
-
-/* Forward reference */
-static void whereClauseClear(WhereClause*);
-
-/*
-** Deallocate all memory associated with a WhereOrInfo object.
-*/
-static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
- whereClauseClear(&p->wc);
- sqlite3DbFree(db, p);
-}
-
-/*
-** Deallocate all memory associated with a WhereAndInfo object.
-*/
-static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
- whereClauseClear(&p->wc);
- sqlite3DbFree(db, p);
-}
-
-/*
-** Deallocate a WhereClause structure. The WhereClause structure
-** itself is not freed. This routine is the inverse of whereClauseInit().
-*/
-static void whereClauseClear(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);
- }
-}
-
-/*
-** 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, u8 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]);
- }
- pTerm = &pWC->a[idx = pWC->nTerm++];
- if( p && ExprHasProperty(p, EP_Unlikely) ){
- pTerm->truthProb = sqlite3LogEst(p->iTable) - 99;
- }else{
- pTerm->truthProb = 1;
- }
- pTerm->pExpr = sqlite3ExprSkipCollate(p);
- pTerm->wtFlags = wtFlags;
- pTerm->pWC = pWC;
- pTerm->iParent = -1;
- return idx;
-}
-
-/*
-** 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.
-*/
-static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
- pWC->op = op;
- if( pExpr==0 ) return;
- if( pExpr->op!=op ){
- whereClauseInsert(pWC, pExpr, 0);
- }else{
- whereSplit(pWC, pExpr->pLeft, op);
- whereSplit(pWC, pExpr->pRight, op);
- }
-}
-
-/*
-** Initialize a WhereMaskSet object
-*/
-#define initMaskSet(P) (P)->n=0
-
-/*
** Return the bitmask for the given cursor number. Return 0 if
** iCursor is not in the set.
*/
-static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
+Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
int i;
assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
for(i=0; i<pMaskSet->n; i++){
@@ -298,174 +174,45 @@ static void createMask(WhereMaskSet *pMaskSet, int iCursor){
}
/*
-** These routines walk (recursively) an expression tree and generate
-** a bitmask indicating which tables are used in that expression
-** tree.
-*/
-static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
-static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
-static Bitmask exprTableUsage(WhereMaskSet *pMaskSet, Expr *p){
- Bitmask mask = 0;
- if( p==0 ) return 0;
- if( p->op==TK_COLUMN ){
- mask = getMask(pMaskSet, p->iTable);
- return mask;
- }
- mask = exprTableUsage(pMaskSet, p->pRight);
- mask |= exprTableUsage(pMaskSet, p->pLeft);
- if( ExprHasProperty(p, EP_xIsSelect) ){
- mask |= exprSelectTableUsage(pMaskSet, p->x.pSelect);
- }else{
- mask |= exprListTableUsage(pMaskSet, p->x.pList);
- }
- return mask;
-}
-static Bitmask exprListTableUsage(WhereMaskSet *pMaskSet, ExprList *pList){
- int i;
- Bitmask mask = 0;
- if( pList ){
- for(i=0; i<pList->nExpr; i++){
- mask |= exprTableUsage(pMaskSet, pList->a[i].pExpr);
- }
- }
- return mask;
-}
-static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
- Bitmask mask = 0;
- while( pS ){
- SrcList *pSrc = pS->pSrc;
- mask |= exprListTableUsage(pMaskSet, pS->pEList);
- mask |= exprListTableUsage(pMaskSet, pS->pGroupBy);
- mask |= exprListTableUsage(pMaskSet, pS->pOrderBy);
- mask |= exprTableUsage(pMaskSet, pS->pWhere);
- mask |= exprTableUsage(pMaskSet, pS->pHaving);
- if( ALWAYS(pSrc!=0) ){
- int i;
- for(i=0; i<pSrc->nSrc; i++){
- mask |= exprSelectTableUsage(pMaskSet, pSrc->a[i].pSelect);
- mask |= exprTableUsage(pMaskSet, pSrc->a[i].pOn);
- }
- }
- pS = pS->pPrior;
- }
- return mask;
-}
-
-/*
-** 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;
-}
-
-/*
-** 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{
- 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 );
- return c;
-}
-
-/*
** 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 */
- int iColumn; /* The column on the LHS of the term. -1 for IPK */
+ 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->aEquiv[pScan->iEquiv-2];
- iColumn = pScan->aEquiv[pScan->iEquiv-1];
+ 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
- && (pScan->iEquiv<=2 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+ && (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->aEquiv)
+ && pScan->nEquiv<ArraySize(pScan->aiCur)
+ && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
){
int j;
- pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
- assert( pX->op==TK_COLUMN );
- for(j=0; j<pScan->nEquiv; j+=2){
- if( pScan->aEquiv[j]==pX->iTable
- && pScan->aEquiv[j+1]==pX->iColumn ){
+ for(j=0; j<pScan->nEquiv; j++){
+ if( pScan->aiCur[j]==pX->iTable
+ && pScan->aiColumn[j]==pX->iColumn ){
break;
}
}
if( j==pScan->nEquiv ){
- pScan->aEquiv[j] = pX->iTable;
- pScan->aEquiv[j+1] = pX->iColumn;
- pScan->nEquiv += 2;
+ pScan->aiCur[j] = pX->iTable;
+ pScan->aiColumn[j] = pX->iColumn;
+ pScan->nEquiv++;
}
}
if( (pTerm->eOperator & pScan->opMask)!=0 ){
@@ -485,11 +232,12 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
continue;
}
}
- if( (pTerm->eOperator & WO_EQ)!=0
+ if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
&& (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
- && pX->iTable==pScan->aEquiv[0]
- && pX->iColumn==pScan->aEquiv[1]
+ && pX->iTable==pScan->aiCur[0]
+ && pX->iColumn==pScan->aiColumn[0]
){
+ testcase( pTerm->eOperator & WO_IS );
continue;
}
pScan->k = k+1;
@@ -502,7 +250,7 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
}
pScan->pWC = pScan->pOrigWC;
k = 0;
- pScan->iEquiv += 2;
+ pScan->iEquiv++;
}
return 0;
}
@@ -531,16 +279,19 @@ static WhereTerm *whereScanInit(
u32 opMask, /* Operator(s) to scan for */
Index *pIdx /* Must be compatible with this index */
){
- int j;
+ 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;
- for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
- if( NEVER(j>pIdx->nColumn) ) return 0;
- }
pScan->zCollName = pIdx->azColl[j];
}else{
pScan->idxaff = 0;
@@ -548,10 +299,10 @@ static WhereTerm *whereScanInit(
}
pScan->opMask = opMask;
pScan->k = 0;
- pScan->aEquiv[0] = iCur;
- pScan->aEquiv[1] = iColumn;
- pScan->nEquiv = 2;
- pScan->iEquiv = 2;
+ pScan->aiCur[0] = iCur;
+ pScan->aiColumn[0] = iColumn;
+ pScan->nEquiv = 1;
+ pScan->iEquiv = 1;
return whereScanNext(pScan);
}
@@ -561,15 +312,16 @@ static WhereTerm *whereScanInit(
** 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
-** aEquiv[] array holds X and all its equivalents, with each SQL variable
-** taking up two slots in aEquiv[]. The first slot is for the cursor number
-** and the second is for the column number. There are 22 slots in aEquiv[]
-** 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>.
+** 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
@@ -578,7 +330,7 @@ static WhereTerm *whereScanInit(
** 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.
*/
-static WhereTerm *findTerm(
+WhereTerm *sqlite3WhereFindTerm(
WhereClause *pWC, /* The WHERE clause to be searched */
int iCur, /* Cursor number of LHS */
int iColumn, /* Column number of LHS */
@@ -591,9 +343,11 @@ static WhereTerm *findTerm(
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&WO_EQ)!=0 ){
+ if( p->prereqRight==0 && (p->eOperator&op)!=0 ){
+ testcase( p->eOperator & WO_IS );
return p;
}
if( pResult==0 ) pResult = p;
@@ -603,892 +357,171 @@ static WhereTerm *findTerm(
return pResult;
}
-/* Forward reference */
-static void exprAnalyze(SrcList*, WhereClause*, int);
-
/*
-** Call exprAnalyze on all terms in a WHERE clause.
+** 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 void exprAnalyzeAll(
- SrcList *pTabList, /* the FROM clause */
- WhereClause *pWC /* the WHERE clause to be analyzed */
+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;
- for(i=pWC->nTerm-1; i>=0; i--){
- exprAnalyze(pTabList, pWC, i);
- }
-}
+ const char *zColl = pIdx->azColl[iCol];
-#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.
-*/
-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)
- ){
- /* 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_NONE);
- 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);
- }
+ 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;
}
- }else{
- z = 0;
}
}
- sqlite3ValueFree(pVal);
- return (z!=0);
+ return -1;
}
-#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
-** Check to see if the given expression is of the form
-**
-** column MATCH expr
-**
-** If it is then return TRUE. If not, return FALSE.
+** Return TRUE if the iCol-th column of index pIdx is NOT NULL
*/
-static int isMatchOfColumn(
- Expr *pExpr /* Test this expression */
-){
- ExprList *pList;
-
- if( pExpr->op!=TK_FUNCTION ){
- return 0;
- }
- if( sqlite3StrICmp(pExpr->u.zToken,"match")!=0 ){
- return 0;
- }
- pList = pExpr->x.pList;
- if( pList->nExpr!=2 ){
- return 0;
- }
- if( pList->a[1].pExpr->op != TK_COLUMN ){
- return 0;
- }
- return 1;
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
+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 */
-/*
-** 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;
}
}
-#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)
-**
-** 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 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 2. 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 2 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 2 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:
+** Return true if the DISTINCT expression-list passed as the third argument
+** is redundant.
**
-** If neither case 1 nor case 2 apply, then leave the eOperator set to
-** zero. This term is not useful for search.
+** A DISTINCT list is redundant if any subset of the columns in the
+** DISTINCT list are collectively unique and individually non-null.
*/
-static void exprAnalyzeOrTerm(
- SrcList *pSrc, /* the FROM clause */
- WhereClause *pWC, /* the complete WHERE clause */
- int idxTerm /* Index of the OR-term to be analyzed */
+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 */
){
- 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 */
+ Table *pTab;
+ Index *pIdx;
+ int i;
+ int iBase;
- /*
- ** 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;
- whereClauseInit(pOrWc, pWInfo);
- whereSplit(pOrWc, pExpr, TK_OR);
- exprAnalyzeAll(pSrc, pOrWc);
- if( db->mallocFailed ) return;
- assert( pOrWc->nTerm>=2 );
+ /* 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;
- /*
- ** Compute the set of tables that might satisfy cases 1 or 2.
+ /* 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.
*/
- 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;
- whereClauseInit(pAndWC, pWC->pWInfo);
- whereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
- exprAnalyzeAll(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 |= getMask(&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 = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
- if( pOrTerm->wtFlags & TERM_VIRTUAL ){
- WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
- b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor);
- }
- indexable &= b;
- if( (pOrTerm->eOperator & WO_EQ)==0 ){
- chngToIN = 0;
- }else{
- chngToIN &= b;
- }
- }
+ 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;
}
- /*
- ** Record the set of tables that satisfy case 2. The set might be
- ** empty.
- */
- pOrInfo->indexable = indexable;
- pTerm->eOperator = indexable==0 ? 0 : WO_OR;
-
- /*
- ** 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.
+ /* Loop through all indices on the table, checking each to see if it makes
+ ** the DISTINCT qualifier redundant. It does so if:
**
- ** 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.
+ ** 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.
**
- ** Note that terms of the form "table.column1=table.column2" (the
- ** same table on both sizes of the ==) cannot be optimized.
+ ** 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.
*/
- 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 & getMask(&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==getMask(&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;
- }
- }
+ 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;
}
}
-
- /* 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];
- pWC->a[idxNew].iParent = idxTerm;
- pTerm->nChild = 1;
- }else{
- sqlite3ExprListDelete(db, pList);
- }
- pTerm->eOperator = WO_NOOP; /* case 1 trumps case 2 */
+ if( i==pIdx->nKeyCol ){
+ /* This index implies that the DISTINCT qualifier is redundant. */
+ return 1;
}
}
+
+ return 0;
}
-#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
+
/*
-** 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.
+** Estimate the logarithm of the input value to base 2.
*/
-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; /* LIKE/GLOB distinguishes case */
- int op; /* Top-level operator. pExpr->op */
- Parse *pParse = pWInfo->pParse; /* Parsing context */
- sqlite3 *db = pParse->db; /* Database connection */
-
- if( db->mallocFailed ){
- return;
- }
- pTerm = &pWC->a[idxTerm];
- pMaskSet = &pWInfo->sMaskSet;
- pExpr = pTerm->pExpr;
- assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
- prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
- op = pExpr->op;
- if( op==TK_IN ){
- assert( pExpr->pRight==0 );
- if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- pTerm->prereqRight = exprSelectTableUsage(pMaskSet, pExpr->x.pSelect);
- }else{
- pTerm->prereqRight = exprListTableUsage(pMaskSet, pExpr->x.pList);
- }
- }else if( op==TK_ISNULL ){
- pTerm->prereqRight = 0;
- }else{
- pTerm->prereqRight = exprTableUsage(pMaskSet, pExpr->pRight);
- }
- prereqAll = exprTableUsage(pMaskSet, pExpr);
- if( ExprHasProperty(pExpr, EP_FromJoin) ){
- Bitmask x = getMask(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) ){
- Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
- Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
- u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
- if( pLeft->op==TK_COLUMN ){
- pTerm->leftCursor = pLeft->iTable;
- pTerm->u.leftColumn = pLeft->iColumn;
- pTerm->eOperator = operatorMask(op) & opMask;
- }
- if( pRight && pRight->op==TK_COLUMN ){
- 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];
- pNew->iParent = idxTerm;
- pTerm = &pWC->a[idxTerm];
- pTerm->nChild = 1;
- pTerm->wtFlags |= TERM_COPIED;
- if( pExpr->op==TK_EQ
- && !ExprHasProperty(pExpr, EP_FromJoin)
- && OptimizationEnabled(db, SQLITE_Transitive)
- ){
- pTerm->eOperator |= WO_EQUIV;
- eExtraOp = WO_EQUIV;
- }
- }else{
- pDup = pExpr;
- pNew = pTerm;
- }
- exprCommute(pParse, pDup);
- pLeft = sqlite3ExprSkipCollate(pDup->pLeft);
- pNew->leftCursor = pLeft->iTable;
- pNew->u.leftColumn = pLeft->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];
- pWC->a[idxNew].iParent = idxTerm;
- }
- pTerm->nChild = 2;
- }
-#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( 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 */
-
- pLeft = pExpr->x.pList->a[1].pExpr;
- pStr2 = sqlite3ExprDup(db, pStr1, 0);
- 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, TERM_VIRTUAL|TERM_DYNAMIC);
- 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, TERM_VIRTUAL|TERM_DYNAMIC);
- testcase( idxNew2==0 );
- exprAnalyze(pSrc, pWC, idxNew2);
- pTerm = &pWC->a[idxTerm];
- if( isComplete ){
- pWC->a[idxNew1].iParent = idxTerm;
- pWC->a[idxNew2].iParent = idxTerm;
- pTerm->nChild = 2;
- }
- }
-#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) ){
- 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 = exprTableUsage(pMaskSet, pRight);
- prereqColumn = exprTableUsage(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->iParent = idxTerm;
- pTerm = &pWC->a[idxTerm];
- pTerm->nChild = 1;
- 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. This
- ** TERM_VNULL tag will suppress the not-null check at the beginning
- ** of the loop. Without the TERM_VNULL flag, the not-null check at
- ** the start of the loop will prevent any results from being returned.
- */
- if( pExpr->op==TK_NOTNULL
- && pExpr->pLeft->op==TK_COLUMN
- && pExpr->pLeft->iColumn>=0
- && OptimizationEnabled(db, SQLITE_Stat3)
- ){
- 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;
- pNewTerm->iParent = idxTerm;
- pTerm = &pWC->a[idxTerm];
- pTerm->nChild = 1;
- 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;
+static LogEst estLog(LogEst N){
+ return N<=10 ? 0 : sqlite3LogEst(N) - 33;
}
/*
-** This function searches pList for an entry that matches the iCol-th column
-** of index pIdx.
+** Convert OP_Column opcodes to OP_Copy in previously generated code.
**
-** 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( ALWAYS(pColl) && 0==sqlite3StrICmp(pColl->zName, zColl) ){
- return i;
- }
- }
- }
-
- return -1;
-}
-
-/*
-** Return true if the DISTINCT expression-list passed as the third argument
-** is redundant.
+** 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.
**
-** A DISTINCT list is redundant if the database contains some subset of
-** columns that are unique and non-null.
+** 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 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 */
+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) */
){
- 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++){
- i16 iCol = pIdx->aiColumn[i];
- if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){
- int iIdxCol = findIndexCol(pParse, pDistinct, iBase, pIdx, i);
- if( iIdxCol<0 || pTab->aCol[iCol].notNull==0 ){
- break;
- }
+ 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;
}
}
- 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;
}
/*
@@ -1549,11 +582,12 @@ static int termCanDriveIndex(
){
char aff;
if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
- if( (pTerm->eOperator & WO_EQ)==0 ) 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
@@ -1590,6 +624,11 @@ static void constructAutomaticIndex(
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. */
@@ -1605,6 +644,17 @@ static void constructAutomaticIndex(
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);
@@ -1617,7 +667,9 @@ static void constructAutomaticIndex(
sentWarning = 1;
}
if( (idxCols & cMask)==0 ){
- if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ) return;
+ if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
+ goto end_auto_index_create;
+ }
pLoop->aLTerm[nKeyCol++] = pTerm;
idxCols |= cMask;
}
@@ -1637,7 +689,7 @@ static void constructAutomaticIndex(
** if they go out of sync.
*/
extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
- mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol;
+ mxBitCol = MIN(BMS-1,pTable->nCol);
testcase( pTable->nCol==BMS-1 );
testcase( pTable->nCol==BMS-2 );
for(i=0; i<mxBitCol; i++){
@@ -1646,11 +698,10 @@ static void constructAutomaticIndex(
if( pSrc->colUsed & MASKBIT(BMS-1) ){
nKeyCol += pTable->nCol - BMS + 1;
}
- pLoop->wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY;
/* Construct the Index object to describe this index */
pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
- if( pIdx==0 ) return;
+ if( pIdx==0 ) goto end_auto_index_create;
pLoop->u.btree.pIndex = pIdx;
pIdx->zName = "auto-index";
pIdx->pTable = pTable;
@@ -1667,7 +718,7 @@ static void constructAutomaticIndex(
idxCols |= cMask;
pIdx->aiColumn[n] = pTerm->u.leftColumn;
pColl = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
- pIdx->azColl[n] = ALWAYS(pColl) ? pColl->zName : "BINARY";
+ pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
n++;
}
}
@@ -1679,20 +730,20 @@ static void constructAutomaticIndex(
for(i=0; i<mxBitCol; i++){
if( extraCols & MASKBIT(i) ){
pIdx->aiColumn[n] = i;
- pIdx->azColl[n] = "BINARY";
+ 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] = "BINARY";
+ pIdx->azColl[n] = sqlite3StrBINARY;
n++;
}
}
assert( n==nKeyCol );
- pIdx->aiColumn[n] = -1;
- pIdx->azColl[n] = "BINARY";
+ pIdx->aiColumn[n] = XN_ROWID;
+ pIdx->azColl[n] = sqlite3StrBINARY;
/* Create the automatic index */
assert( pLevel->iIdxCur>=0 );
@@ -1702,18 +753,48 @@ static void constructAutomaticIndex(
VdbeComment((v, "for %s", pTable->zName));
/* Fill the automatic index with content */
- addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
+ 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);
- sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0);
+ regBase = sqlite3GenerateIndexKey(
+ pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
+ );
sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
- sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
+ 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 */
@@ -1726,6 +807,7 @@ static void constructAutomaticIndex(
static sqlite3_index_info *allocateIndexInfo(
Parse *pParse,
WhereClause *pWC,
+ Bitmask mUnusable, /* Ignore terms with these prereqs */
struct SrcList_item *pSrc,
ExprList *pOrderBy
){
@@ -1742,12 +824,15 @@ static sqlite3_index_info *allocateIndexInfo(
** 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))==0 ) continue;
+ if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV|WO_IS))==0 ) continue;
if( pTerm->wtFlags & TERM_VNULL ) continue;
+ assert( pTerm->u.leftColumn>=(-1) );
nTerm++;
}
@@ -1795,16 +880,22 @@ static sqlite3_index_info *allocateIndexInfo(
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))==0 ) continue;
+ 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
@@ -1873,18 +964,21 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
}
#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 pVal
-** aStat[1] Est. number of rows equal to pVal
+** aStat[0] Est. number of rows less than pRec
+** aStat[1] Est. number of rows equal to pRec
**
-** Return SQLITE_OK on success.
+** 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 void whereKeyStats(
+static int whereKeyStats(
Parse *pParse, /* Database connection */
Index *pIdx, /* Index to consider domain of */
UnpackedRecord *pRec, /* Vector of values to consider */
@@ -1893,67 +987,158 @@ static void whereKeyStats(
){
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 i = pIdx->nSample; /* Smallest sample larger than or equal to pRec */
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 );
- iCol = pRec->nField - 1;
assert( pIdx->nSample>0 );
- assert( pRec->nField>0 && iCol<pIdx->nSampleCol );
+ 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{
- iTest = (iMin+i)/2;
- res = sqlite3VdbeRecordCompare(aSample[iTest].n, aSample[iTest].p, pRec);
+ 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{
- i = iTest;
+ iSample = iTest;
+ iCol = n-1;
}
- }while( res && iMin<i );
+ }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( res==0 ){
- /* If (res==0) is true, then sample $i must be equal to pRec */
- assert( i<pIdx->nSample );
- assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)
- || pParse->db->mallocFailed );
- }else{
- /* Otherwise, pRec must be smaller than sample $i and larger than
- ** sample ($i-1). */
- assert( i==pIdx->nSample
- || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
- || pParse->db->mallocFailed );
- assert( i==0
- || sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
- || pParse->db->mallocFailed );
+ 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 */
- /* At this point, aSample[i] is the first sample that is greater than
- ** or equal to pVal. Or if i==pIdx->nSample, then all samples are less
- ** than pVal. If aSample[i]==pVal, then res==0.
- */
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{
- tRowcnt iLower, iUpper, iGap;
- if( i==0 ){
- iLower = 0;
- iUpper = aSample[0].anLt[iCol];
+ /* 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{
- i64 nRow0 = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
- iUpper = i>=pIdx->nSample ? nRow0 : aSample[i].anLt[iCol];
- iLower = aSample[i-1].anEq[iCol] + aSample[i-1].anLt[iCol];
+ iUpper = aSample[i].anLt[iCol];
}
- aStat[1] = pIdx->aAvgEq[iCol];
+
if( iLower>=iUpper ){
iGap = 0;
}else{
@@ -1965,7 +1150,12 @@ static void whereKeyStats(
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 */
@@ -1992,6 +1182,21 @@ static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
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
@@ -2041,8 +1246,7 @@ static int whereRangeSkipScanEst(
int nLower = -1;
int nUpper = p->nSample+1;
int rc = SQLITE_OK;
- int iCol = p->aiColumn[nEq];
- u8 aff = iCol>=0 ? p->pTable->aCol[iCol].affinity : SQLITE_AFF_INTEGER;
+ u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);
CollSeq *pColl;
sqlite3_value *p1 = 0; /* Value extracted from pLower */
@@ -2116,7 +1320,7 @@ static int whereRangeSkipScanEst(
** 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 index of the index
+** 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:
@@ -2132,7 +1336,7 @@ static int whereRangeSkipScanEst(
**
** 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, this is the number of
+** 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.
**
@@ -2156,10 +1360,7 @@ static int whereRangeScanEst(
Index *p = pLoop->u.btree.pIndex;
int nEq = pLoop->u.btree.nEq;
- if( p->nSample>0
- && nEq<p->nSampleCol
- && OptimizationEnabled(pParse->db, SQLITE_Stat3)
- ){
+ if( p->nSample>0 && nEq<p->nSampleCol ){
if( nEq==pBuilder->nRecValid ){
UnpackedRecord *pRec = pBuilder->pRec;
tRowcnt a[2];
@@ -2175,29 +1376,30 @@ static int whereRangeScanEst(
** 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 used.
+ ** ($P:$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 $U is available, both values
** of iUpper are requested of whereKeyStats() and the smaller used.
+ **
+ ** The number of rows between the two bounds is then just iUpper-iLower.
*/
- tRowcnt iLower;
- tRowcnt iUpper;
+ tRowcnt iLower; /* Rows less than the lower bound */
+ tRowcnt iUpper; /* Rows less than the upper bound */
+ int iLwrIdx = -2; /* aSample[] for the lower bound */
+ int iUprIdx = -1; /* aSample[] for the upper bound */
if( pRec ){
testcase( pRec->nField!=pBuilder->nRecValid );
pRec->nField = pBuilder->nRecValid;
}
- if( nEq==p->nKeyCol ){
- aff = SQLITE_AFF_INTEGER;
- }else{
- aff = p->pTable->aCol[p->aiColumn[nEq]].affinity;
- }
+ aff = sqlite3IndexColumnAffinity(pParse->db, p, nEq);
+ assert( nEq!=p->nKeyCol || aff==SQLITE_AFF_INTEGER );
/* Determine iLower and iUpper using ($P) only. */
if( nEq==0 ){
iLower = 0;
- iUpper = sqlite3LogEstToInt(p->aiRowLogEst[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(). */
@@ -2221,7 +1423,7 @@ static int whereRangeScanEst(
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
if( rc==SQLITE_OK && bOk ){
tRowcnt iNew;
- whereKeyStats(pParse, p, pRec, 0, a);
+ 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--;
@@ -2236,7 +1438,7 @@ static int whereRangeScanEst(
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
if( rc==SQLITE_OK && bOk ){
tRowcnt iNew;
- whereKeyStats(pParse, p, pRec, 1, a);
+ 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--;
@@ -2248,6 +1450,11 @@ static int whereRangeScanEst(
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) );
}
@@ -2272,12 +1479,15 @@ static int whereRangeScanEst(
nNew = whereRangeAdjust(pLower, nOut);
nNew = whereRangeAdjust(pUpper, nNew);
- /* TUNING: If there is both an upper and lower limit, assume the range is
+ /* 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 && pUpper ) nNew -= 20;
+ if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
+ nNew -= 20;
+ }
nOut -= (pLower!=0) + (pUpper!=0);
if( nNew<10 ) nNew = 10;
@@ -2318,1455 +1528,95 @@ static int whereEqualScanEst(
){
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 = p->pTable->aCol[p->aiColumn[nEq-1]].affinity;
- 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 */
-
-/*
-** 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.
-*/
-static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
- if( pTerm
- && (pTerm->wtFlags & TERM_CODED)==0
- && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
- && (pLevel->notReady & pTerm->prereqAll)==0
- ){
- pTerm->wtFlags |= TERM_CODED;
- if( pTerm->iParent>=0 ){
- WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
- if( (--pOther->nChild)==0 ){
- disableTerm(pLevel, pOther);
- }
- }
- }
-}
-
-/*
-** Code an OP_Affinity opcode to apply the column affinity string zAff
-** to the n registers starting at base.
-**
-** As an optimization, SQLITE_AFF_NONE entries (which are no-ops) at the
-** beginning and end of zAff are ignored. If all entries in zAff are
-** SQLITE_AFF_NONE, 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_NONE entries at the beginning
- ** and end of the affinity string.
- */
- while( n>0 && zAff[0]==SQLITE_AFF_NONE ){
- n--;
- base++;
- zAff++;
- }
- while( n>1 && zAff[n-1]==SQLITE_AFF_NONE ){
- 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 ){
- 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 NONE affinity are set to
-** SQLITE_AFF_NONE. 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 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_NONE.
-*/
-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->u.btree.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(v, 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);
- assert( pIdx->aiColumn[j]>=0 );
- VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName));
- }
- }
-
- /* 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( sqlite3ExprCanBeNull(pRight) ){
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
- VdbeCoverage(v);
- }
- if( zAff ){
- if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){
- zAff[j] = SQLITE_AFF_NONE;
- }
- if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
- zAff[j] = SQLITE_AFF_NONE;
- }
- }
- }
- }
- *pzAff = zAff;
- return regBase;
-}
-
-#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);
-}
-
-/*
-** 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, Table *pTab){
- Index *pIndex = pLoop->u.btree.pIndex;
- u16 nEq = pLoop->u.btree.nEq;
- u16 nSkip = pLoop->u.btree.nSkip;
- int i, j;
- Column *aCol = pTab->aCol;
- i16 *aiColumn = pIndex->aiColumn;
-
- if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
- sqlite3StrAccumAppend(pStr, " (", 2);
- for(i=0; i<nEq; i++){
- char *z = aiColumn[i] < 0 ? "rowid" : aCol[aiColumn[i]].zName;
- if( i>=nSkip ){
- explainAppendTerm(pStr, i, z, "=");
- }else{
- if( i ) sqlite3StrAccumAppend(pStr, " AND ", 5);
- sqlite3XPrintf(pStr, 0, "ANY(%s)", z);
- }
- }
-
- j = i;
- if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
- char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
- explainAppendTerm(pStr, i++, z, ">");
- }
- if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
- char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName;
- explainAppendTerm(pStr, i, z, "<");
- }
- sqlite3StrAccumAppend(pStr, ")", 1);
-}
-
-/*
-** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
-** command. If the query being compiled is an EXPLAIN QUERY PLAN, a single
-** record is added to the output to describe the table scan strategy in
-** pLevel.
-*/
-static void explainOneScan(
- 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() */
-){
-#ifndef SQLITE_DEBUG
- 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;
-
- 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, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
- str.db = db;
- 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_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, pItem->pTab);
- }
- }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
- const char *zRange;
- if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
- zRange = "(rowid=?)";
- }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
- zRange = "(rowid>? AND rowid<?)";
- }else if( flags&WHERE_BTM_LIMIT ){
- zRange = "(rowid>?)";
- }else{
- assert( flags&WHERE_TOP_LIMIT);
- zRange = "(rowid<?)";
- }
- sqlite3StrAccumAppendAll(&str, " USING INTEGER PRIMARY KEY ");
- sqlite3StrAccumAppendAll(&str, zRange);
- }
-#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);
- sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC);
- }
-}
-#else
-# define explainOneScan(u,v,w,x,y,z)
-#endif /* SQLITE_OMIT_EXPLAIN */
-
-
-/*
-** Generate code for the start of the iLevel-th loop in the WHERE clause
-** implementation described by pWInfo.
-*/
-static Bitmask codeOneLoopStart(
- 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 & ~getMask(&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].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->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->op = OP_VNext;
- pLevel->p1 = iCur;
- 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;
- }
- 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->u.btree.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->u.btree.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;
- }
- if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
- pRangeEnd = pLoop->aLTerm[j++];
- nExtraReg = 1;
- if( pRangeStart==0
- && (j = pIdx->aiColumn[nEq])>=0
- && pIdx->pTable->aCol[j].notNull==0
- ){
- bSeekPastNull = 1;
- }
- }
- assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
-
- /* 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.
- */
- regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
- assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
- if( zStartAff ) cEndAff = zStartAff[nEq];
- addrNxt = pLevel->addrNxt;
-
- /* 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);
- }
-
- 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);
- 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_NONE){
- /* Since the comparison is to be performed with no conversions
- ** applied to the operands, set the affinity to apply to pRight to
- ** SQLITE_AFF_NONE. */
- zStartAff[nEq] = SQLITE_AFF_NONE;
- }
- if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
- zStartAff[nEq] = SQLITE_AFF_NONE;
- }
- }
- 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);
- if( (pRangeEnd->wtFlags & TERM_VNULL)==0
- && sqlite3ExprCanBeNull(pRight)
- ){
- sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
- VdbeCoverage(v);
- }
- if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_NONE
- && !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);
- 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;
- testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
- testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
- if( pWC->a[iTerm].wtFlags & (TERM_ORINFO|TERM_VIRTUAL) ) continue;
- if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
- pExpr = sqlite3ExprDup(db, pExpr, 0);
- pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
- }
- if( pAndExpr ){
- pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
- }
- }
+ UnpackedRecord *pRec = pBuilder->pRec;
+ u8 aff; /* Column affinity */
+ int rc; /* Subfunction return code */
+ tRowcnt a[2]; /* Statistics */
+ int bOk;
- /* 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;
- 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 j1 = 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;
- explainOneScan(
- pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
- );
- /* 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);
- j1 = 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];
- sqlite3ExprCodeGetColumn(pParse, pTab, iCol, iCur, r+iPk, 0);
- }
+ assert( nEq>=1 );
+ assert( nEq<=p->nColumn );
+ assert( p->aSample!=0 );
+ assert( p->nSample>0 );
+ assert( pBuilder->nRecValid<nEq );
- /* 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 ){
- j1 = 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);
- }
+ /* 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;
+ }
- /* Release the array of temp registers */
- sqlite3ReleaseTempRange(pParse, r, nPk);
- }
- }
+ /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
+ ** below would return the same value. */
+ if( nEq>=p->nColumn ){
+ *pnRow = 1;
+ return SQLITE_OK;
+ }
- /* 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( j1 ) sqlite3VdbeJumpHere(v, j1);
-
- /* 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;
- }
+ 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;
- /* 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));
- sqlite3VdbeAddOp2(v, OP_Goto, 0, 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->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{
- 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;
- }
- }
+ 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 */
- /* 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;
- 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;
- }
- sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
- pTerm->wtFlags |= TERM_CODED;
- }
+#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 */
- /* 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_EQUIV|WO_EQ) ) 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 = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
- if( pAlt==0 ) continue;
- if( pAlt->wtFlags & (TERM_CODED) ) continue;
- testcase( pAlt->eOperator & WO_EQ );
- 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);
- }
+ 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;
}
- /* 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;
- }
+ if( rc==SQLITE_OK ){
+ if( nRowEst > nRow0 ) nRowEst = nRow0;
+ *pnRow = nRowEst;
+ WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
}
-
- return pLevel->notReady;
+ assert( pBuilder->nRecValid==nRecValid );
+ return rc;
}
+#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
+
#ifdef WHERETRACE_ENABLED
/*
@@ -3781,9 +1631,10 @@ static void whereTermPrint(WhereTerm *pTerm, int iTerm){
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\n",
- iTerm, pTerm, zType, pTerm->leftCursor, pTerm->truthProb,
- pTerm->eOperator);
+ 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);
}
}
@@ -3826,7 +1677,7 @@ static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
sqlite3_free(z);
}
if( p->wsFlags & WHERE_SKIPSCAN ){
- sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->u.btree.nSkip);
+ sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
}else{
sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
}
@@ -3862,7 +1713,6 @@ static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
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);
- sqlite3KeyInfoUnref(p->u.btree.pIndex->pKeyInfo);
sqlite3DbFree(db, p->u.btree.pIndex);
p->u.btree.pIndex = 0;
}
@@ -3926,7 +1776,14 @@ static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
if( ALWAYS(pWInfo) ){
- whereClauseClear(&pWInfo->sWC);
+ 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;
@@ -3937,10 +1794,11 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
}
/*
-** Return TRUE if both of the following are true:
+** 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
@@ -3948,19 +1806,25 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
**
** 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.
+** 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 >= pY->nLTerm ) return 0; /* X is not a subset of Y */
+ 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;
}
@@ -3982,33 +1846,24 @@ static int whereLoopCheaperProperSubset(
** 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.
-**
-** This adjustment is omitted for SKIPSCAN loops. In a SKIPSCAN loop, the
-** WhereLoop.nLTerm field is not an accurate measure of the number of WHERE
-** clause terms covered, since some of the first nLTerm entries in aLTerm[]
-** will be NULL (because they are skipped). That makes it more difficult
-** to compare the loops. We could add extra code to do the comparison, and
-** perhaps we will someday. But SKIPSCAN is sufficiently uncommon, and this
-** adjustment is sufficient minor, that it is very difficult to construct
-** a test case where the extra code would improve the query plan. Better
-** to avoid the added complexity and just omit cost adjustments to SKIPSCAN
-** loops.
*/
static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
- if( (pTemplate->wsFlags & WHERE_SKIPSCAN)!=0 ) return;
for(; p; p=p->pNextLoop){
if( p->iTab!=pTemplate->iTab ) continue;
if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
- if( (p->wsFlags & WHERE_SKIPSCAN)!=0 ) continue;
if( whereLoopCheaperProperSubset(p, pTemplate) ){
/* Adjust pTemplate cost downward so that it is cheaper than its
- ** subset p */
+ ** 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;
}
@@ -4053,8 +1908,9 @@ static WhereLoop **whereLoopFindLesser(
/* Any loop using an appliation-defined index (or PRIMARY KEY or
** UNIQUE constraint) with one or more == constraints is better
- ** than an automatic index. */
+ ** 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
@@ -4124,18 +1980,20 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
** and prereqs.
*/
if( pBuilder->pOrSet!=0 ){
+ if( pTemplate->nLTerm ){
#if WHERETRACE_ENABLED
- u16 n = pBuilder->pOrSet->n;
- int x =
+ u16 n = pBuilder->pOrSet->n;
+ int x =
#endif
- whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+ 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);
- }
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf(x?" or-%d: ":" or-X: ", n);
+ whereLoopPrint(pTemplate, pBuilder->pWC);
+ }
#endif
+ }
return SQLITE_OK;
}
@@ -4213,10 +2071,30 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
** 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.
-**
-** In the current implementation, the first extra WHERE clause term reduces
-** the number of output rows by a factor of 10 and each additional term
-** reduces the number of output rows by sqrt(2).
+*
+** 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 */
@@ -4225,9 +2103,10 @@ static void whereLoopOutputAdjust(
){
WhereTerm *pTerm, *pX;
Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
- int i, j;
- int nEq = 0; /* Number of = constraints not within likely()/unlikely() */
+ 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;
@@ -4240,20 +2119,27 @@ static void whereLoopOutputAdjust(
}
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 ) nEq++;
+ 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;
+ }
}
}
}
- /* TUNING: If there is at least one equality constraint in the WHERE
- ** clause that does not have a likelihood() explicitly assigned to it
- ** then do not let the estimated number of output rows exceed half
- ** the number of rows in the table. */
- if( nEq && pLoop->nOut>nRow-10 ){
- pLoop->nOut = nRow - 10;
- }
+ if( pLoop->nOut > nRow-iReduce ) pLoop->nOut = nRow - iReduce;
}
/*
@@ -4294,10 +2180,9 @@ static int whereLoopAddBtreeIndex(
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->u.btree.nSkip */
+ 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 iCol; /* Index of the column in the table */
int rc = SQLITE_OK; /* Return code */
LogEst rSize; /* Number of rows in the table */
LogEst rLogSize; /* Logarithm of table size */
@@ -4310,65 +2195,26 @@ static int whereLoopAddBtreeIndex(
assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
if( pNew->wsFlags & WHERE_BTM_LIMIT ){
opMask = WO_LT|WO_LE;
- }else if( pProbe->tnum<=0 || (pSrc->jointype & JT_LEFT)!=0 ){
+ }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_ISNULL|WO_GT|WO_GE|WO_LT|WO_LE;
+ 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 );
- iCol = pProbe->aiColumn[pNew->u.btree.nEq];
- pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
- opMask, pProbe);
saved_nEq = pNew->u.btree.nEq;
- saved_nSkip = pNew->u.btree.nSkip;
+ 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);
-
- /* 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->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->u.btree.nSkip++;
- pNew->aLTerm[pNew->nLTerm++] = 0;
- pNew->wsFlags |= WHERE_SKIPSCAN;
- nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
- if( pTerm ){
- /* TUNING: When estimating skip-scan for a term that is also indexable,
- ** multiply the cost of the skip-scan by 2.0, to make it a little less
- ** desirable than the regular index lookup. */
- nIter += 10; assert( 10==sqlite3LogEst(2) );
- }
- 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->u.btree.nSkip = saved_nSkip;
- }
for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
u16 eOp = pTerm->eOperator; /* Shorthand for pTerm->eOperator */
LogEst rCostIdx;
@@ -4378,12 +2224,16 @@ static int whereLoopAddBtreeIndex(
int nRecValid = pBuilder->nRecValid;
#endif
if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
- && (iCol<0 || pSrc->pTab->aCol[iCol].notNull)
+ && 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;
@@ -4410,10 +2260,14 @@ static int whereLoopAddBtreeIndex(
assert( nIn>0 ); /* RHS always has 2 or more terms... The parser
** changes "x IN (?)" into "x=?". */
- }else if( eOp & (WO_EQ) ){
+ }else if( eOp & (WO_EQ|WO_IS) ){
+ int iCol = pProbe->aiColumn[saved_nEq];
pNew->wsFlags |= WHERE_COLUMN_EQ;
- if( iCol<0 || (nInMul==0 && pNew->u.btree.nEq==pProbe->nKeyCol-1) ){
- if( iCol>=0 && !IsUniqueIndex(pProbe) ){
+ 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;
@@ -4427,6 +2281,17 @@ static int whereLoopAddBtreeIndex(
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 );
@@ -4449,10 +2314,10 @@ static int whereLoopAddBtreeIndex(
whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
}else{
int nEq = ++pNew->u.btree.nEq;
- assert( eOp & (WO_ISNULL|WO_EQ|WO_IN) );
+ assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );
assert( pNew->nOut==saved_nOut );
- if( pTerm->truthProb<=0 && iCol>=0 ){
+ if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
assert( (eOp & WO_IN) || nIn==0 );
testcase( eOp & WO_IN );
pNew->nOut += pTerm->truthProb;
@@ -4463,12 +2328,12 @@ static int whereLoopAddBtreeIndex(
if( nInMul==0
&& pProbe->nSample
&& pNew->u.btree.nEq<=pProbe->nSampleCol
- && OptimizationEnabled(db, SQLITE_Stat3)
&& ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
){
Expr *pExpr = pTerm->pExpr;
- if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){
+ 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{
@@ -4531,10 +2396,45 @@ static int whereLoopAddBtreeIndex(
}
pNew->prereq = saved_prereq;
pNew->u.btree.nEq = saved_nEq;
- pNew->u.btree.nSkip = saved_nSkip;
+ 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;
}
@@ -4552,18 +2452,25 @@ static int indexMightHelpWithOrderBy(
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 ) return 0;
- if( pExpr->iTable==iCursor ){
+ 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;
@@ -4593,8 +2500,17 @@ static Bitmask columnsInIndex(Index *pIdx){
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++){
- if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab) ) return 1;
+ Expr *pExpr = pTerm->pExpr;
+ if( sqlite3ExprImpliesExpr(pExpr, pWhere, iTab)
+ && (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)
+ ){
+ return 1;
+ }
}
return 0;
}
@@ -4663,9 +2579,9 @@ static int whereLoopAddBtree(
pWC = pBuilder->pWC;
assert( !IsVirtual(pSrc->pTab) );
- if( pSrc->pIndex ){
+ if( pSrc->pIBIndex ){
/* An INDEXED BY clause specifies a particular index to use */
- pProbe = pSrc->pIndex;
+ pProbe = pSrc->pIBIndex;
}else if( !HasRowid(pTab) ){
pProbe = pTab->pIndex;
}else{
@@ -4685,7 +2601,7 @@ static int whereLoopAddBtree(
aiRowEstPk[0] = pTab->nRowLogEst;
aiRowEstPk[1] = 0;
pFirst = pSrc->pTab->pIndex;
- if( pSrc->notIndexed==0 ){
+ 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;
@@ -4697,14 +2613,14 @@ static int whereLoopAddBtree(
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/* Automatic indexes */
- if( !pBuilder->pOrSet
+ if( !pBuilder->pOrSet /* Not part of an OR optimization */
+ && (pWInfo->wctrlFlags & WHERE_NO_AUTOINDEX)==0
&& (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
- && pSrc->pIndex==0
- && !pSrc->viaCoroutine
- && !pSrc->notIndexed
- && HasRowid(pTab)
- && !pSrc->isCorrelated
- && !pSrc->isRecursive
+ && 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;
@@ -4713,7 +2629,7 @@ static int whereLoopAddBtree(
if( pTerm->prereqRight & pNew->maskSelf ) continue;
if( termCanDriveIndex(pTerm, pSrc, 0) ){
pNew->u.btree.nEq = 1;
- pNew->u.btree.nSkip = 0;
+ pNew->nSkip = 0;
pNew->u.btree.pIndex = 0;
pNew->nLTerm = 1;
pNew->aLTerm[0] = pTerm;
@@ -4754,7 +2670,7 @@ static int whereLoopAddBtree(
}
rSize = pProbe->aiRowLogEst[0];
pNew->u.btree.nEq = 0;
- pNew->u.btree.nSkip = 0;
+ pNew->nSkip = 0;
pNew->nLTerm = 0;
pNew->iSortIdx = 0;
pNew->rSetup = 0;
@@ -4825,7 +2741,7 @@ static int whereLoopAddBtree(
/* If there was an INDEXED BY clause, then only that one index is
** considered. */
- if( pSrc->pIndex ) break;
+ if( pSrc->pIBIndex ) break;
}
return rc;
}
@@ -4834,10 +2750,32 @@ static int whereLoopAddBtree(
/*
** 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
+ 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 */
@@ -4858,6 +2796,7 @@ static int whereLoopAddVirtual(
WhereLoop *pNew;
int rc = SQLITE_OK;
+ assert( (mExtra & mUnusable)==0 );
pWInfo = pBuilder->pWInfo;
pParse = pWInfo->pParse;
db = pParse->db;
@@ -4866,7 +2805,7 @@ static int whereLoopAddVirtual(
pSrc = &pWInfo->pTabList->a[pNew->iTab];
pTab = pSrc->pTab;
assert( IsVirtual(pTab) );
- pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy);
+ pIdxInfo = allocateIndexInfo(pParse, pWC, mUnusable, pSrc,pBuilder->pOrderBy);
if( pIdxInfo==0 ) return SQLITE_NOMEM;
pNew->prereq = 0;
pNew->rSetup = 0;
@@ -4896,7 +2835,7 @@ static int whereLoopAddVirtual(
if( (pTerm->eOperator & WO_IN)!=0 ){
seenIn = 1;
}
- if( pTerm->prereqRight!=0 ){
+ if( (pTerm->prereqRight & ~mExtra)!=0 ){
seenVar = 1;
}else if( (pTerm->eOperator & WO_IN)==0 ){
pIdxCons->usable = 1;
@@ -4904,7 +2843,7 @@ static int whereLoopAddVirtual(
break;
case 1: /* Constants with IN operators */
assert( seenIn );
- pIdxCons->usable = (pTerm->prereqRight==0);
+ pIdxCons->usable = (pTerm->prereqRight & ~mExtra)==0;
break;
case 2: /* Variables without IN */
assert( seenVar );
@@ -4924,6 +2863,8 @@ static int whereLoopAddVirtual(
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;
@@ -4969,6 +2910,7 @@ static int whereLoopAddVirtual(
** (2) Multiple outputs from a single IN value will not merge
** together. */
pIdxInfo->orderByConsumed = 0;
+ pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
}
}
}
@@ -4984,6 +2926,14 @@ static int whereLoopAddVirtual(
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);
@@ -5003,7 +2953,11 @@ whereLoopAddVtab_exit:
** Add WhereLoop entries to handle OR terms. This works for either
** btrees or virtual tables.
*/
-static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
+static int whereLoopAddOr(
+ WhereLoopBuilder *pBuilder,
+ Bitmask mExtra,
+ Bitmask mUnusable
+){
WhereInfo *pWInfo = pBuilder->pWInfo;
WhereClause *pWC;
WhereLoop *pNew;
@@ -5062,14 +3016,14 @@ static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pItem->pTab) ){
- rc = whereLoopAddVirtual(&sSubBuild, mExtra);
+ rc = whereLoopAddVirtual(&sSubBuild, mExtra, mUnusable);
}else
#endif
{
rc = whereLoopAddBtree(&sSubBuild, mExtra);
}
if( rc==SQLITE_OK ){
- rc = whereLoopAddOr(&sSubBuild, mExtra);
+ rc = whereLoopAddOr(&sSubBuild, mExtra, mUnusable);
}
assert( rc==SQLITE_OK || sCur.n==0 );
if( sCur.n==0 ){
@@ -5131,33 +3085,43 @@ static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
int iTab;
SrcList *pTabList = pWInfo->pTabList;
struct SrcList_item *pItem;
+ struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];
sqlite3 *db = pWInfo->pParse->db;
- int nTabList = pWInfo->nLevel;
int rc = SQLITE_OK;
- u8 priorJoinType = 0;
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; iTab<nTabList; iTab++, pItem++){
+ for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
+ Bitmask mUnusable = 0;
pNew->iTab = iTab;
- pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
- if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
+ 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->jointype;
+ priorJointype = pItem->fg.jointype;
if( IsVirtual(pItem->pTab) ){
- rc = whereLoopAddVirtual(pBuilder, mExtra);
+ 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);
+ rc = whereLoopAddOr(pBuilder, mExtra, mUnusable);
}
mPrior |= pNew->maskSelf;
if( rc || db->mallocFailed ) break;
}
+
whereLoopClear(db, pNew);
return rc;
}
@@ -5263,10 +3227,10 @@ static i8 wherePathSatisfiesOrderBy(
pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
if( pOBExpr->op!=TK_COLUMN ) continue;
if( pOBExpr->iTable!=iCur ) continue;
- pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
- ~ready, WO_EQ|WO_ISNULL, 0);
+ pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+ ~ready, WO_EQ|WO_ISNULL|WO_IS, 0);
if( pTerm==0 ) continue;
- if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){
+ 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;
@@ -5275,6 +3239,7 @@ static i8 wherePathSatisfiesOrderBy(
if( !pColl ) pColl = db->pDfltColl;
z2 = pColl->zName;
if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+ testcase( pTerm->pExpr->op==TK_IS );
}
obSat |= MASKBIT(i);
}
@@ -5290,7 +3255,8 @@ static i8 wherePathSatisfiesOrderBy(
nKeyCol = pIndex->nKeyCol;
nColumn = pIndex->nColumn;
assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
- assert( pIndex->aiColumn[nColumn-1]==(-1) || !HasRowid(pIndex->pTable));
+ assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
+ || !HasRowid(pIndex->pTable));
isOrderDistinct = IsUniqueIndex(pIndex);
}
@@ -5304,8 +3270,8 @@ static i8 wherePathSatisfiesOrderBy(
/* Skip over == and IS NULL terms */
if( j<pLoop->u.btree.nEq
- && pLoop->u.btree.nSkip==0
- && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
+ && pLoop->nSkip==0
+ && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL|WO_IS))!=0
){
if( i & WO_ISNULL ){
testcase( isOrderDistinct );
@@ -5322,7 +3288,7 @@ static i8 wherePathSatisfiesOrderBy(
revIdx = pIndex->aSortOrder[j];
if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
}else{
- iColumn = -1;
+ iColumn = XN_ROWID;
revIdx = 0;
}
@@ -5348,9 +3314,15 @@ static i8 wherePathSatisfiesOrderBy(
testcase( wctrlFlags & WHERE_GROUPBY );
testcase( wctrlFlags & WHERE_DISTINCTBY );
if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
- if( pOBExpr->op!=TK_COLUMN ) continue;
- if( pOBExpr->iTable!=iCur ) continue;
- if( pOBExpr->iColumn!=iColumn ) continue;
+ 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;
@@ -5399,7 +3371,7 @@ static i8 wherePathSatisfiesOrderBy(
Bitmask mTerm;
if( MASKBIT(i) & obSat ) continue;
p = pOrderBy->a[i].pExpr;
- mTerm = exprTableUsage(&pWInfo->sMaskSet,p);
+ mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);
if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
if( (mTerm&~orderDistinctMask)==0 ){
obSat |= MASKBIT(i);
@@ -5581,10 +3553,10 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
/* Seed the search with a single WherePath containing zero WhereLoops.
**
- ** TUNING: Do not let the number of iterations go above 25. If the cost
- ** of computing an automatic index is not paid back within the first 25
+ ** 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, 46); assert( 46==sqlite3LogEst(25) );
+ aFrom[0].nRow = MIN(pParse->nQueryLoop, 48); assert( 48==sqlite3LogEst(28) );
nFrom = 1;
assert( aFrom[0].isOrdered==0 );
if( nOrderBy ){
@@ -5758,7 +3730,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
}
#ifdef WHERETRACE_ENABLED /* >=2 */
- if( sqlite3WhereTrace>=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",
@@ -5822,7 +3794,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
pWInfo->revMask = pFrom->revLoop;
}
if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
- && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr
+ && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
){
Bitmask revMask = 0;
int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy,
@@ -5872,14 +3844,15 @@ static int whereShortCut(WhereLoopBuilder *pBuilder){
pItem = pWInfo->pTabList->a;
pTab = pItem->pTab;
if( IsVirtual(pTab) ) return 0;
- if( pItem->zIndex ) return 0;
+ if( pItem->fg.isIndexedBy ) return 0;
iCur = pItem->iCursor;
pWC = &pWInfo->sWC;
pLoop = pBuilder->pNew;
pLoop->wsFlags = 0;
- pLoop->u.btree.nSkip = 0;
- pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 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;
@@ -5888,15 +3861,17 @@ static int whereShortCut(WhereLoopBuilder *pBuilder){
pLoop->rRun = 33; /* 33==sqlite3LogEst(10) */
}else{
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+ int opMask;
assert( pLoop->aLTermSpace==pLoop->aLTerm );
- assert( ArraySize(pLoop->aLTermSpace)==4 );
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 = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
+ 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;
@@ -5915,7 +3890,7 @@ static int whereShortCut(WhereLoopBuilder *pBuilder){
if( pLoop->wsFlags ){
pLoop->nOut = (LogEst)1;
pWInfo->a[0].pWLoop = pLoop;
- pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur);
+ pLoop->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
pWInfo->a[0].iTabCur = iCur;
pWInfo->nRowOut = 1;
if( pWInfo->pOrderBy ) pWInfo->nOBSat = pWInfo->pOrderBy->nExpr;
@@ -6039,7 +4014,12 @@ WhereInfo *sqlite3WhereBegin(
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;
@@ -6095,6 +4075,7 @@ WhereInfo *sqlite3WhereBegin(
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;
@@ -6109,8 +4090,8 @@ WhereInfo *sqlite3WhereBegin(
** subexpression is separated by an AND operator.
*/
initMaskSet(pMaskSet);
- whereClauseInit(&pWInfo->sWC, pWInfo);
- whereSplit(&pWInfo->sWC, pWhere, TK_AND);
+ 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.
@@ -6134,14 +4115,12 @@ WhereInfo *sqlite3WhereBegin(
/* Assign a bit from the bitmask to every term in the FROM clause.
**
- ** When assigning bitmask values to FROM clause cursors, it must be
- ** the case that if X is the bitmask for the N-th FROM clause term then
- ** the bitmask for all FROM clause terms to the left of the N-th term
- ** is (X-1). An expression from the ON clause of a LEFT JOIN can use
- ** its Expr.iRightJoinTable value to find the bitmask of the right table
- ** of the join. Subtracting one from the right table bitmask gives a
- ** bitmask for all tables to the left of the join. Knowing the bitmask
- ** for all tables to the left of a left join is important. Ticket #3015.
+ ** 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
@@ -6150,27 +4129,18 @@ WhereInfo *sqlite3WhereBegin(
*/
for(ii=0; ii<pTabList->nSrc; ii++){
createMask(pMaskSet, pTabList->a[ii].iCursor);
+ sqlite3WhereTabFuncArgs(pParse, &pTabList->a[ii], &pWInfo->sWC);
}
-#ifndef NDEBUG
- {
- Bitmask toTheLeft = 0;
- for(ii=0; ii<pTabList->nSrc; ii++){
- Bitmask m = getMask(pMaskSet, pTabList->a[ii].iCursor);
- assert( (m-1)==toTheLeft );
- toTheLeft |= m;
- }
+#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. Note that exprAnalyze() might
- ** add new virtual terms onto the end of the WHERE clause. We do not
- ** want to analyze these virtual terms, so start analyzing at the end
- ** and work forward so that the added virtual terms are never processed.
- */
- exprAnalyzeAll(pTabList, &pWInfo->sWC);
- if( db->mallocFailed ){
- goto whereBeginError;
- }
+ /* 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) ){
@@ -6184,10 +4154,10 @@ WhereInfo *sqlite3WhereBegin(
}
/* Construct the WhereLoop objects */
- WHERETRACE(0xffff,("*** Optimizer Start ***\n"));
+ WHERETRACE(0xffff,("*** Optimizer Start *** (wctrlFlags: 0x%x)\n",
+ wctrlFlags));
#if defined(WHERETRACE_ENABLED)
- /* Display all terms of the WHERE clause */
- if( sqlite3WhereTrace & 0x100 ){
+ 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);
@@ -6199,13 +4169,12 @@ WhereInfo *sqlite3WhereBegin(
rc = whereLoopAddAll(&sWLB);
if( rc ) goto whereBeginError;
- /* Display all of the WhereLoop objects if wheretrace is enabled */
-#ifdef WHERETRACE_ENABLED /* !=0 */
- if( sqlite3WhereTrace ){
+#ifdef WHERETRACE_ENABLED
+ if( sqlite3WhereTrace ){ /* Display all of the WhereLoop objects */
WhereLoop *p;
int i;
- static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
- "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+ 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);
@@ -6226,9 +4195,8 @@ WhereInfo *sqlite3WhereBegin(
if( pParse->nErr || NEVER(db->mallocFailed) ){
goto whereBeginError;
}
-#ifdef WHERETRACE_ENABLED /* !=0 */
+#ifdef WHERETRACE_ENABLED
if( sqlite3WhereTrace ){
- int ii;
sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
if( pWInfo->nOBSat>0 ){
sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask);
@@ -6258,12 +4226,14 @@ WhereInfo *sqlite3WhereBegin(
&& pResultSet!=0
&& OptimizationEnabled(db, SQLITE_OmitNoopJoin)
){
- Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
- if( sWLB.pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, sWLB.pOrderBy);
+ 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].jointype & JT_LEFT)==0 ) break;
+ if( (pWInfo->pTabList->a[pLoop->iTab].fg.jointype & JT_LEFT)==0 ) break;
if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
&& (pLoop->wsFlags & WHERE_ONEROW)==0
){
@@ -6290,21 +4260,28 @@ WhereInfo *sqlite3WhereBegin(
/* 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 a single row.
+ ** the statement to update or delete a single row.
*/
assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
- if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0
- && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){
- pWInfo->okOnePass = 1;
- if( HasRowid(pTabList->a[0].pTab) ){
- pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;
+ 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.
*/
- notReady = ~(Bitmask)0;
for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
Table *pTab; /* Table to open */
int iDb; /* Index of database containing table/index */
@@ -6329,15 +4306,15 @@ WhereInfo *sqlite3WhereBegin(
if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
&& (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
int op = OP_OpenRead;
- if( pWInfo->okOnePass ){
+ 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->okOnePass && pTab->nCol==BMS-1 );
- testcase( !pWInfo->okOnePass && pTab->nCol==BMS );
- if( !pWInfo->okOnePass && pTab->nCol<BMS && HasRowid(pTab) ){
+ 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++){}
@@ -6345,6 +4322,18 @@ WhereInfo *sqlite3WhereBegin(
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);
}
@@ -6361,7 +4350,7 @@ WhereInfo *sqlite3WhereBegin(
** WITHOUT ROWID table. No need for a separate index */
iIndexCur = pLevel->iTabCur;
op = 0;
- }else if( pWInfo->okOnePass ){
+ }else if( pWInfo->eOnePass!=ONEPASS_OFF ){
Index *pJ = pTabItem->pTab->pIndex;
iIndexCur = iIdxCur;
assert( wctrlFlags & WHERE_ONEPASS_DESIRED );
@@ -6383,11 +4372,31 @@ WhereInfo *sqlite3WhereBegin(
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);
- notReady &= ~getMask(&pWInfo->sMaskSet, pTabItem->iCursor);
}
pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
if( db->mallocFailed ) goto whereBeginError;
@@ -6398,7 +4407,10 @@ WhereInfo *sqlite3WhereBegin(
*/
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,
@@ -6406,10 +4418,15 @@ WhereInfo *sqlite3WhereBegin(
if( db->mallocFailed ) goto whereBeginError;
}
#endif
- explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags);
+ addrExplain = sqlite3WhereExplainOneScan(
+ pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags
+ );
pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
- notReady = codeOneLoopStart(pWInfo, ii, notReady);
+ 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. */
@@ -6467,15 +4484,26 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen);
sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
}
- sqlite3DbFree(db, pLevel->u.in.aInLoop);
}
sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
if( pLevel->addrSkip ){
- sqlite3VdbeAddOp2(v, OP_Goto, 0, 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
@@ -6489,7 +4517,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
if( pLevel->op==OP_Return ){
sqlite3VdbeAddOp2(v, OP_Gosub, pLevel->p1, pLevel->addrFirst);
}else{
- sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrFirst);
+ sqlite3VdbeGoto(v, pLevel->addrFirst);
}
sqlite3VdbeJumpHere(v, addr);
}
@@ -6513,26 +4541,12 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
pLoop = pLevel->pWLoop;
/* For a co-routine, change all OP_Column references to the table of
- ** the co-routine into OP_SCopy of result contained in a register.
+ ** the co-routine into OP_Copy of result contained in a register.
** OP_Rowid becomes OP_Null.
*/
- if( pTabItem->viaCoroutine && !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 ){
- pOp->opcode = OP_Copy;
- pOp->p1 = pOp->p2 + pTabItem->regResult;
- pOp->p2 = pOp->p3;
- pOp->p3 = 0;
- }else if( pOp->opcode==OP_Rowid ){
- pOp->opcode = OP_Null;
- pOp->p1 = 0;
- pOp->p3 = 0;
- }
- }
+ if( pTabItem->fg.viaCoroutine && !db->mallocFailed ){
+ translateColumnToCopy(v, pLevel->addrBody, pLevel->iTabCur,
+ pTabItem->regResult, 0);
continue;
}
@@ -6546,7 +4560,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
&& (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
){
int ws = pLoop->wsFlags;
- if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
+ if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
}
if( (ws & WHERE_INDEXED)!=0
@@ -6573,7 +4587,10 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
}else if( pLoop->wsFlags & WHERE_MULTI_OR ){
pIdx = pLevel->u.pCovidx;
}
- if( pIdx && !db->mallocFailed ){
+ if( pIdx
+ && (pWInfo->eOnePass==ONEPASS_OFF || !HasRowid(pIdx->pTable))
+ && !db->mallocFailed
+ ){
last = sqlite3VdbeCurrentAddr(v);
k = pLevel->addrBody;
pOp = sqlite3VdbeGetOp(v, k);
@@ -6585,6 +4602,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
if( !HasRowid(pTab) ){
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
x = pPk->aiColumn[x];
+ assert( x>=0 );
}
x = sqlite3ColumnOfIndex(pIdx, x);
if( x>=0 ){
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