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Unified Diff: third_party/sqlite/sqlite-src-3100200/src/whereexpr.c

Issue 2846743003: [sql] Remove SQLite 3.10.2 reference directory. (Closed)
Patch Set: Created 3 years, 8 months ago
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Index: third_party/sqlite/sqlite-src-3100200/src/whereexpr.c
diff --git a/third_party/sqlite/sqlite-src-3100200/src/whereexpr.c b/third_party/sqlite/sqlite-src-3100200/src/whereexpr.c
deleted file mode 100644
index 99a97079be378d654311847305e2b4cd93460208..0000000000000000000000000000000000000000
--- a/third_party/sqlite/sqlite-src-3100200/src/whereexpr.c
+++ /dev/null
@@ -1,1358 +0,0 @@
-/*
-** 2015-06-08
-**
-** The author disclaims copyright to this source code. In place of
-** a legal notice, here is a blessing:
-**
-** May you do good and not evil.
-** May you find forgiveness for yourself and forgive others.
-** May you share freely, never taking more than you give.
-**
-*************************************************************************
-** This module contains C code that generates VDBE code used to process
-** the WHERE clause of SQL statements.
-**
-** This file was originally part of where.c but was split out to improve
-** readability and editabiliity. This file contains utility routines for
-** analyzing Expr objects in the WHERE clause.
-*/
-#include "sqliteInt.h"
-#include "whereInt.h"
-
-/* Forward declarations */
-static void exprAnalyze(SrcList*, WhereClause*, int);
-
-/*
-** Deallocate all memory associated with a WhereOrInfo object.
-*/
-static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
- sqlite3WhereClauseClear(&p->wc);
- sqlite3DbFree(db, p);
-}
-
-/*
-** Deallocate all memory associated with a WhereAndInfo object.
-*/
-static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
- sqlite3WhereClauseClear(&p->wc);
- sqlite3DbFree(db, p);
-}
-
-/*
-** Add a single new WhereTerm entry to the WhereClause object pWC.
-** The new WhereTerm object is constructed from Expr p and with wtFlags.
-** The index in pWC->a[] of the new WhereTerm is returned on success.
-** 0 is returned if the new WhereTerm could not be added due to a memory
-** allocation error. The memory allocation failure will be recorded in
-** the db->mallocFailed flag so that higher-level functions can detect it.
-**
-** This routine will increase the size of the pWC->a[] array as necessary.
-**
-** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
-** for freeing the expression p is assumed by the WhereClause object pWC.
-** This is true even if this routine fails to allocate a new WhereTerm.
-**
-** WARNING: This routine might reallocate the space used to store
-** WhereTerms. All pointers to WhereTerms should be invalidated after
-** calling this routine. Such pointers may be reinitialized by referencing
-** the pWC->a[] array.
-*/
-static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
- WhereTerm *pTerm;
- int idx;
- testcase( wtFlags & TERM_VIRTUAL );
- if( pWC->nTerm>=pWC->nSlot ){
- WhereTerm *pOld = pWC->a;
- sqlite3 *db = pWC->pWInfo->pParse->db;
- pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
- if( pWC->a==0 ){
- if( wtFlags & TERM_DYNAMIC ){
- sqlite3ExprDelete(db, p);
- }
- pWC->a = pOld;
- return 0;
- }
- memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
- if( pOld!=pWC->aStatic ){
- sqlite3DbFree(db, pOld);
- }
- pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
- memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm));
- }
- pTerm = &pWC->a[idx = pWC->nTerm++];
- if( p && ExprHasProperty(p, EP_Unlikely) ){
- pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
- }else{
- pTerm->truthProb = 1;
- }
- pTerm->pExpr = sqlite3ExprSkipCollate(p);
- pTerm->wtFlags = wtFlags;
- pTerm->pWC = pWC;
- pTerm->iParent = -1;
- return idx;
-}
-
-/*
-** Return TRUE if the given operator is one of the operators that is
-** allowed for an indexable WHERE clause term. The allowed operators are
-** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
-*/
-static int allowedOp(int op){
- assert( TK_GT>TK_EQ && TK_GT<TK_GE );
- assert( TK_LT>TK_EQ && TK_LT<TK_GE );
- assert( TK_LE>TK_EQ && TK_LE<TK_GE );
- assert( TK_GE==TK_EQ+4 );
- return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;
-}
-
-/*
-** Commute a comparison operator. Expressions of the form "X op Y"
-** are converted into "Y op X".
-**
-** If left/right precedence rules come into play when determining the
-** collating sequence, then COLLATE operators are adjusted to ensure
-** that the collating sequence does not change. For example:
-** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
-** the left hand side of a comparison overrides any collation sequence
-** attached to the right. For the same reason the EP_Collate flag
-** is not commuted.
-*/
-static void exprCommute(Parse *pParse, Expr *pExpr){
- u16 expRight = (pExpr->pRight->flags & EP_Collate);
- u16 expLeft = (pExpr->pLeft->flags & EP_Collate);
- assert( allowedOp(pExpr->op) && pExpr->op!=TK_IN );
- if( expRight==expLeft ){
- /* Either X and Y both have COLLATE operator or neither do */
- if( expRight ){
- /* Both X and Y have COLLATE operators. Make sure X is always
- ** used by clearing the EP_Collate flag from Y. */
- pExpr->pRight->flags &= ~EP_Collate;
- }else if( sqlite3ExprCollSeq(pParse, pExpr->pLeft)!=0 ){
- /* Neither X nor Y have COLLATE operators, but X has a non-default
- ** collating sequence. So add the EP_Collate marker on X to cause
- ** it to be searched first. */
- pExpr->pLeft->flags |= EP_Collate;
- }
- }
- SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
- if( pExpr->op>=TK_GT ){
- assert( TK_LT==TK_GT+2 );
- assert( TK_GE==TK_LE+2 );
- assert( TK_GT>TK_EQ );
- assert( TK_GT<TK_LE );
- assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
- pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
- }
-}
-
-/*
-** Translate from TK_xx operator to WO_xx bitmask.
-*/
-static u16 operatorMask(int op){
- u16 c;
- assert( allowedOp(op) );
- if( op==TK_IN ){
- c = WO_IN;
- }else if( op==TK_ISNULL ){
- c = WO_ISNULL;
- }else if( op==TK_IS ){
- c = WO_IS;
- }else{
- assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
- c = (u16)(WO_EQ<<(op-TK_EQ));
- }
- assert( op!=TK_ISNULL || c==WO_ISNULL );
- assert( op!=TK_IN || c==WO_IN );
- assert( op!=TK_EQ || c==WO_EQ );
- assert( op!=TK_LT || c==WO_LT );
- assert( op!=TK_LE || c==WO_LE );
- assert( op!=TK_GT || c==WO_GT );
- assert( op!=TK_GE || c==WO_GE );
- assert( op!=TK_IS || c==WO_IS );
- return c;
-}
-
-
-#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
-/*
-** Check to see if the given expression is a LIKE or GLOB operator that
-** can be optimized using inequality constraints. Return TRUE if it is
-** so and false if not.
-**
-** In order for the operator to be optimizible, the RHS must be a string
-** literal that does not begin with a wildcard. The LHS must be a column
-** that may only be NULL, a string, or a BLOB, never a number. (This means
-** that virtual tables cannot participate in the LIKE optimization.) The
-** collating sequence for the column on the LHS must be appropriate for
-** the operator.
-*/
-static int isLikeOrGlob(
- Parse *pParse, /* Parsing and code generating context */
- Expr *pExpr, /* Test this expression */
- Expr **ppPrefix, /* Pointer to TK_STRING expression with pattern prefix */
- int *pisComplete, /* True if the only wildcard is % in the last character */
- int *pnoCase /* True if uppercase is equivalent to lowercase */
-){
- const char *z = 0; /* String on RHS of LIKE operator */
- Expr *pRight, *pLeft; /* Right and left size of LIKE operator */
- ExprList *pList; /* List of operands to the LIKE operator */
- int c; /* One character in z[] */
- int cnt; /* Number of non-wildcard prefix characters */
- char wc[3]; /* Wildcard characters */
- sqlite3 *db = pParse->db; /* Database connection */
- sqlite3_value *pVal = 0;
- int op; /* Opcode of pRight */
-
- if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
- return 0;
- }
-#ifdef SQLITE_EBCDIC
- if( *pnoCase ) return 0;
-#endif
- pList = pExpr->x.pList;
- pLeft = pList->a[1].pExpr;
- if( pLeft->op!=TK_COLUMN
- || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT
- || IsVirtual(pLeft->pTab) /* Value might be numeric */
- ){
- /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must
- ** be the name of an indexed column with TEXT affinity. */
- return 0;
- }
- assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */
-
- pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
- op = pRight->op;
- if( op==TK_VARIABLE ){
- Vdbe *pReprepare = pParse->pReprepare;
- int iCol = pRight->iColumn;
- pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);
- if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
- z = (char *)sqlite3_value_text(pVal);
- }
- sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);
- assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
- }else if( op==TK_STRING ){
- z = pRight->u.zToken;
- }
- if( z ){
- cnt = 0;
- while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
- cnt++;
- }
- if( cnt!=0 && 255!=(u8)z[cnt-1] ){
- Expr *pPrefix;
- *pisComplete = c==wc[0] && z[cnt+1]==0;
- pPrefix = sqlite3Expr(db, TK_STRING, z);
- if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
- *ppPrefix = pPrefix;
- if( op==TK_VARIABLE ){
- Vdbe *v = pParse->pVdbe;
- sqlite3VdbeSetVarmask(v, pRight->iColumn);
- if( *pisComplete && pRight->u.zToken[1] ){
- /* If the rhs of the LIKE expression is a variable, and the current
- ** value of the variable means there is no need to invoke the LIKE
- ** function, then no OP_Variable will be added to the program.
- ** This causes problems for the sqlite3_bind_parameter_name()
- ** API. To work around them, add a dummy OP_Variable here.
- */
- int r1 = sqlite3GetTempReg(pParse);
- sqlite3ExprCodeTarget(pParse, pRight, r1);
- sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
- sqlite3ReleaseTempReg(pParse, r1);
- }
- }
- }else{
- z = 0;
- }
- }
-
- sqlite3ValueFree(pVal);
- return (z!=0);
-}
-#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
-
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-/*
-** Check to see if the given expression is of the form
-**
-** column OP expr
-**
-** where OP is one of MATCH, GLOB, LIKE or REGEXP and "column" is a
-** column of a virtual table.
-**
-** If it is then return TRUE. If not, return FALSE.
-*/
-static int isMatchOfColumn(
- Expr *pExpr, /* Test this expression */
- unsigned char *peOp2 /* OUT: 0 for MATCH, or else an op2 value */
-){
- struct Op2 {
- const char *zOp;
- unsigned char eOp2;
- } aOp[] = {
- { "match", SQLITE_INDEX_CONSTRAINT_MATCH },
- { "glob", SQLITE_INDEX_CONSTRAINT_GLOB },
- { "like", SQLITE_INDEX_CONSTRAINT_LIKE },
- { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }
- };
- ExprList *pList;
- Expr *pCol; /* Column reference */
- int i;
-
- if( pExpr->op!=TK_FUNCTION ){
- return 0;
- }
- pList = pExpr->x.pList;
- if( pList==0 || pList->nExpr!=2 ){
- return 0;
- }
- pCol = pList->a[1].pExpr;
- if( pCol->op!=TK_COLUMN || !IsVirtual(pCol->pTab) ){
- return 0;
- }
- for(i=0; i<ArraySize(aOp); i++){
- if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
- *peOp2 = aOp[i].eOp2;
- return 1;
- }
- }
- return 0;
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-/*
-** If the pBase expression originated in the ON or USING clause of
-** a join, then transfer the appropriate markings over to derived.
-*/
-static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
- if( pDerived ){
- pDerived->flags |= pBase->flags & EP_FromJoin;
- pDerived->iRightJoinTable = pBase->iRightJoinTable;
- }
-}
-
-/*
-** Mark term iChild as being a child of term iParent
-*/
-static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
- pWC->a[iChild].iParent = iParent;
- pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
- pWC->a[iParent].nChild++;
-}
-
-/*
-** Return the N-th AND-connected subterm of pTerm. Or if pTerm is not
-** a conjunction, then return just pTerm when N==0. If N is exceeds
-** the number of available subterms, return NULL.
-*/
-static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){
- if( pTerm->eOperator!=WO_AND ){
- return N==0 ? pTerm : 0;
- }
- if( N<pTerm->u.pAndInfo->wc.nTerm ){
- return &pTerm->u.pAndInfo->wc.a[N];
- }
- return 0;
-}
-
-/*
-** Subterms pOne and pTwo are contained within WHERE clause pWC. The
-** two subterms are in disjunction - they are OR-ed together.
-**
-** If these two terms are both of the form: "A op B" with the same
-** A and B values but different operators and if the operators are
-** compatible (if one is = and the other is <, for example) then
-** add a new virtual AND term to pWC that is the combination of the
-** two.
-**
-** Some examples:
-**
-** x<y OR x=y --> x<=y
-** x=y OR x=y --> x=y
-** x<=y OR x<y --> x<=y
-**
-** The following is NOT generated:
-**
-** x<y OR x>y --> x!=y
-*/
-static void whereCombineDisjuncts(
- SrcList *pSrc, /* the FROM clause */
- WhereClause *pWC, /* The complete WHERE clause */
- WhereTerm *pOne, /* First disjunct */
- WhereTerm *pTwo /* Second disjunct */
-){
- u16 eOp = pOne->eOperator | pTwo->eOperator;
- sqlite3 *db; /* Database connection (for malloc) */
- Expr *pNew; /* New virtual expression */
- int op; /* Operator for the combined expression */
- int idxNew; /* Index in pWC of the next virtual term */
-
- if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
- if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
- if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
- && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
- assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
- assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
- if( sqlite3ExprCompare(pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
- if( sqlite3ExprCompare(pOne->pExpr->pRight, pTwo->pExpr->pRight, -1) )return;
- /* If we reach this point, it means the two subterms can be combined */
- if( (eOp & (eOp-1))!=0 ){
- if( eOp & (WO_LT|WO_LE) ){
- eOp = WO_LE;
- }else{
- assert( eOp & (WO_GT|WO_GE) );
- eOp = WO_GE;
- }
- }
- db = pWC->pWInfo->pParse->db;
- pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
- if( pNew==0 ) return;
- for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }
- pNew->op = op;
- idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
- exprAnalyze(pSrc, pWC, idxNew);
-}
-
-#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
-/*
-** Analyze a term that consists of two or more OR-connected
-** subterms. So in:
-**
-** ... WHERE (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
-** ^^^^^^^^^^^^^^^^^^^^
-**
-** This routine analyzes terms such as the middle term in the above example.
-** A WhereOrTerm object is computed and attached to the term under
-** analysis, regardless of the outcome of the analysis. Hence:
-**
-** WhereTerm.wtFlags |= TERM_ORINFO
-** WhereTerm.u.pOrInfo = a dynamically allocated WhereOrTerm object
-**
-** The term being analyzed must have two or more of OR-connected subterms.
-** A single subterm might be a set of AND-connected sub-subterms.
-** Examples of terms under analysis:
-**
-** (A) t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5
-** (B) x=expr1 OR expr2=x OR x=expr3
-** (C) t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
-** (D) x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
-** (E) (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
-** (F) x>A OR (x=A AND y>=B)
-**
-** CASE 1:
-**
-** If all subterms are of the form T.C=expr for some single column of C and
-** a single table T (as shown in example B above) then create a new virtual
-** term that is an equivalent IN expression. In other words, if the term
-** being analyzed is:
-**
-** x = expr1 OR expr2 = x OR x = expr3
-**
-** then create a new virtual term like this:
-**
-** x IN (expr1,expr2,expr3)
-**
-** CASE 2:
-**
-** If there are exactly two disjuncts and one side has x>A and the other side
-** has x=A (for the same x and A) then add a new virtual conjunct term to the
-** WHERE clause of the form "x>=A". Example:
-**
-** x>A OR (x=A AND y>B) adds: x>=A
-**
-** The added conjunct can sometimes be helpful in query planning.
-**
-** CASE 3:
-**
-** If all subterms are indexable by a single table T, then set
-**
-** WhereTerm.eOperator = WO_OR
-** WhereTerm.u.pOrInfo->indexable |= the cursor number for table T
-**
-** A subterm is "indexable" if it is of the form
-** "T.C <op> <expr>" where C is any column of table T and
-** <op> is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
-** A subterm is also indexable if it is an AND of two or more
-** subsubterms at least one of which is indexable. Indexable AND
-** subterms have their eOperator set to WO_AND and they have
-** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
-**
-** From another point of view, "indexable" means that the subterm could
-** potentially be used with an index if an appropriate index exists.
-** This analysis does not consider whether or not the index exists; that
-** is decided elsewhere. This analysis only looks at whether subterms
-** appropriate for indexing exist.
-**
-** All examples A through E above satisfy case 3. But if a term
-** also satisfies case 1 (such as B) we know that the optimizer will
-** always prefer case 1, so in that case we pretend that case 3 is not
-** satisfied.
-**
-** It might be the case that multiple tables are indexable. For example,
-** (E) above is indexable on tables P, Q, and R.
-**
-** Terms that satisfy case 3 are candidates for lookup by using
-** separate indices to find rowids for each subterm and composing
-** the union of all rowids using a RowSet object. This is similar
-** to "bitmap indices" in other database engines.
-**
-** OTHERWISE:
-**
-** If none of cases 1, 2, or 3 apply, then leave the eOperator set to
-** zero. This term is not useful for search.
-*/
-static void exprAnalyzeOrTerm(
- SrcList *pSrc, /* the FROM clause */
- WhereClause *pWC, /* the complete WHERE clause */
- int idxTerm /* Index of the OR-term to be analyzed */
-){
- WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
- Parse *pParse = pWInfo->pParse; /* Parser context */
- sqlite3 *db = pParse->db; /* Database connection */
- WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */
- Expr *pExpr = pTerm->pExpr; /* The expression of the term */
- int i; /* Loop counters */
- WhereClause *pOrWc; /* Breakup of pTerm into subterms */
- WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */
- WhereOrInfo *pOrInfo; /* Additional information associated with pTerm */
- Bitmask chngToIN; /* Tables that might satisfy case 1 */
- Bitmask indexable; /* Tables that are indexable, satisfying case 2 */
-
- /*
- ** Break the OR clause into its separate subterms. The subterms are
- ** stored in a WhereClause structure containing within the WhereOrInfo
- ** object that is attached to the original OR clause term.
- */
- assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );
- assert( pExpr->op==TK_OR );
- pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));
- if( pOrInfo==0 ) return;
- pTerm->wtFlags |= TERM_ORINFO;
- pOrWc = &pOrInfo->wc;
- sqlite3WhereClauseInit(pOrWc, pWInfo);
- sqlite3WhereSplit(pOrWc, pExpr, TK_OR);
- sqlite3WhereExprAnalyze(pSrc, pOrWc);
- if( db->mallocFailed ) return;
- assert( pOrWc->nTerm>=2 );
-
- /*
- ** Compute the set of tables that might satisfy cases 1 or 3.
- */
- indexable = ~(Bitmask)0;
- chngToIN = ~(Bitmask)0;
- for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
- if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
- WhereAndInfo *pAndInfo;
- assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
- chngToIN = 0;
- pAndInfo = sqlite3DbMallocRaw(db, sizeof(*pAndInfo));
- if( pAndInfo ){
- WhereClause *pAndWC;
- WhereTerm *pAndTerm;
- int j;
- Bitmask b = 0;
- pOrTerm->u.pAndInfo = pAndInfo;
- pOrTerm->wtFlags |= TERM_ANDINFO;
- pOrTerm->eOperator = WO_AND;
- pAndWC = &pAndInfo->wc;
- sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
- sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
- sqlite3WhereExprAnalyze(pSrc, pAndWC);
- pAndWC->pOuter = pWC;
- testcase( db->mallocFailed );
- if( !db->mallocFailed ){
- for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
- assert( pAndTerm->pExpr );
- if( allowedOp(pAndTerm->pExpr->op) ){
- b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
- }
- }
- }
- indexable &= b;
- }
- }else if( pOrTerm->wtFlags & TERM_COPIED ){
- /* Skip this term for now. We revisit it when we process the
- ** corresponding TERM_VIRTUAL term */
- }else{
- Bitmask b;
- b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
- if( pOrTerm->wtFlags & TERM_VIRTUAL ){
- WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
- b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
- }
- indexable &= b;
- if( (pOrTerm->eOperator & WO_EQ)==0 ){
- chngToIN = 0;
- }else{
- chngToIN &= b;
- }
- }
- }
-
- /*
- ** Record the set of tables that satisfy case 3. The set might be
- ** empty.
- */
- pOrInfo->indexable = indexable;
- pTerm->eOperator = indexable==0 ? 0 : WO_OR;
-
- /* For a two-way OR, attempt to implementation case 2.
- */
- if( indexable && pOrWc->nTerm==2 ){
- int iOne = 0;
- WhereTerm *pOne;
- while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){
- int iTwo = 0;
- WhereTerm *pTwo;
- while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){
- whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);
- }
- }
- }
-
- /*
- ** chngToIN holds a set of tables that *might* satisfy case 1. But
- ** we have to do some additional checking to see if case 1 really
- ** is satisfied.
- **
- ** chngToIN will hold either 0, 1, or 2 bits. The 0-bit case means
- ** that there is no possibility of transforming the OR clause into an
- ** IN operator because one or more terms in the OR clause contain
- ** something other than == on a column in the single table. The 1-bit
- ** case means that every term of the OR clause is of the form
- ** "table.column=expr" for some single table. The one bit that is set
- ** will correspond to the common table. We still need to check to make
- ** sure the same column is used on all terms. The 2-bit case is when
- ** the all terms are of the form "table1.column=table2.column". It
- ** might be possible to form an IN operator with either table1.column
- ** or table2.column as the LHS if either is common to every term of
- ** the OR clause.
- **
- ** Note that terms of the form "table.column1=table.column2" (the
- ** same table on both sizes of the ==) cannot be optimized.
- */
- if( chngToIN ){
- int okToChngToIN = 0; /* True if the conversion to IN is valid */
- int iColumn = -1; /* Column index on lhs of IN operator */
- int iCursor = -1; /* Table cursor common to all terms */
- int j = 0; /* Loop counter */
-
- /* Search for a table and column that appears on one side or the
- ** other of the == operator in every subterm. That table and column
- ** will be recorded in iCursor and iColumn. There might not be any
- ** such table and column. Set okToChngToIN if an appropriate table
- ** and column is found but leave okToChngToIN false if not found.
- */
- for(j=0; j<2 && !okToChngToIN; j++){
- pOrTerm = pOrWc->a;
- for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
- assert( pOrTerm->eOperator & WO_EQ );
- pOrTerm->wtFlags &= ~TERM_OR_OK;
- if( pOrTerm->leftCursor==iCursor ){
- /* This is the 2-bit case and we are on the second iteration and
- ** current term is from the first iteration. So skip this term. */
- assert( j==1 );
- continue;
- }
- if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,
- pOrTerm->leftCursor))==0 ){
- /* This term must be of the form t1.a==t2.b where t2 is in the
- ** chngToIN set but t1 is not. This term will be either preceded
- ** or follwed by an inverted copy (t2.b==t1.a). Skip this term
- ** and use its inversion. */
- testcase( pOrTerm->wtFlags & TERM_COPIED );
- testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
- assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
- continue;
- }
- iColumn = pOrTerm->u.leftColumn;
- iCursor = pOrTerm->leftCursor;
- break;
- }
- if( i<0 ){
- /* No candidate table+column was found. This can only occur
- ** on the second iteration */
- assert( j==1 );
- assert( IsPowerOfTwo(chngToIN) );
- assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
- break;
- }
- testcase( j==1 );
-
- /* We have found a candidate table and column. Check to see if that
- ** table and column is common to every term in the OR clause */
- okToChngToIN = 1;
- for(; i>=0 && okToChngToIN; i--, pOrTerm++){
- assert( pOrTerm->eOperator & WO_EQ );
- if( pOrTerm->leftCursor!=iCursor ){
- pOrTerm->wtFlags &= ~TERM_OR_OK;
- }else if( pOrTerm->u.leftColumn!=iColumn ){
- okToChngToIN = 0;
- }else{
- int affLeft, affRight;
- /* If the right-hand side is also a column, then the affinities
- ** of both right and left sides must be such that no type
- ** conversions are required on the right. (Ticket #2249)
- */
- affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);
- affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
- if( affRight!=0 && affRight!=affLeft ){
- okToChngToIN = 0;
- }else{
- pOrTerm->wtFlags |= TERM_OR_OK;
- }
- }
- }
- }
-
- /* At this point, okToChngToIN is true if original pTerm satisfies
- ** case 1. In that case, construct a new virtual term that is
- ** pTerm converted into an IN operator.
- */
- if( okToChngToIN ){
- Expr *pDup; /* A transient duplicate expression */
- ExprList *pList = 0; /* The RHS of the IN operator */
- Expr *pLeft = 0; /* The LHS of the IN operator */
- Expr *pNew; /* The complete IN operator */
-
- for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
- if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
- assert( pOrTerm->eOperator & WO_EQ );
- assert( pOrTerm->leftCursor==iCursor );
- assert( pOrTerm->u.leftColumn==iColumn );
- pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
- pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
- pLeft = pOrTerm->pExpr->pLeft;
- }
- assert( pLeft!=0 );
- pDup = sqlite3ExprDup(db, pLeft, 0);
- pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0, 0);
- if( pNew ){
- int idxNew;
- transferJoinMarkings(pNew, pExpr);
- assert( !ExprHasProperty(pNew, EP_xIsSelect) );
- pNew->x.pList = pList;
- idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
- testcase( idxNew==0 );
- exprAnalyze(pSrc, pWC, idxNew);
- pTerm = &pWC->a[idxTerm];
- markTermAsChild(pWC, idxNew, idxTerm);
- }else{
- sqlite3ExprListDelete(db, pList);
- }
- pTerm->eOperator = WO_NOOP; /* case 1 trumps case 3 */
- }
- }
-}
-#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
-
-/*
-** We already know that pExpr is a binary operator where both operands are
-** column references. This routine checks to see if pExpr is an equivalence
-** relation:
-** 1. The SQLITE_Transitive optimization must be enabled
-** 2. Must be either an == or an IS operator
-** 3. Not originating in the ON clause of an OUTER JOIN
-** 4. The affinities of A and B must be compatible
-** 5a. Both operands use the same collating sequence OR
-** 5b. The overall collating sequence is BINARY
-** If this routine returns TRUE, that means that the RHS can be substituted
-** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
-** This is an optimization. No harm comes from returning 0. But if 1 is
-** returned when it should not be, then incorrect answers might result.
-*/
-static int termIsEquivalence(Parse *pParse, Expr *pExpr){
- char aff1, aff2;
- CollSeq *pColl;
- const char *zColl1, *zColl2;
- if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
- if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
- if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
- aff1 = sqlite3ExprAffinity(pExpr->pLeft);
- aff2 = sqlite3ExprAffinity(pExpr->pRight);
- if( aff1!=aff2
- && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
- ){
- return 0;
- }
- pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
- if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
- pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
- /* Since pLeft and pRight are both a column references, their collating
- ** sequence should always be defined. */
- zColl1 = ALWAYS(pColl) ? pColl->zName : 0;
- pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
- zColl2 = ALWAYS(pColl) ? pColl->zName : 0;
- return sqlite3StrICmp(zColl1, zColl2)==0;
-}
-
-/*
-** Recursively walk the expressions of a SELECT statement and generate
-** a bitmask indicating which tables are used in that expression
-** tree.
-*/
-static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){
- Bitmask mask = 0;
- while( pS ){
- SrcList *pSrc = pS->pSrc;
- mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);
- mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
- mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
- mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
- mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
- if( ALWAYS(pSrc!=0) ){
- int i;
- for(i=0; i<pSrc->nSrc; i++){
- mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);
- mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
- }
- }
- pS = pS->pPrior;
- }
- return mask;
-}
-
-/*
-** Expression pExpr is one operand of a comparison operator that might
-** be useful for indexing. This routine checks to see if pExpr appears
-** in any index. Return TRUE (1) if pExpr is an indexed term and return
-** FALSE (0) if not. If TRUE is returned, also set *piCur to the cursor
-** number of the table that is indexed and *piColumn to the column number
-** of the column that is indexed, or -2 if an expression is being indexed.
-**
-** If pExpr is a TK_COLUMN column reference, then this routine always returns
-** true even if that particular column is not indexed, because the column
-** might be added to an automatic index later.
-*/
-static int exprMightBeIndexed(
- SrcList *pFrom, /* The FROM clause */
- Bitmask mPrereq, /* Bitmask of FROM clause terms referenced by pExpr */
- Expr *pExpr, /* An operand of a comparison operator */
- int *piCur, /* Write the referenced table cursor number here */
- int *piColumn /* Write the referenced table column number here */
-){
- Index *pIdx;
- int i;
- int iCur;
- if( pExpr->op==TK_COLUMN ){
- *piCur = pExpr->iTable;
- *piColumn = pExpr->iColumn;
- return 1;
- }
- if( mPrereq==0 ) return 0; /* No table references */
- if( (mPrereq&(mPrereq-1))!=0 ) return 0; /* Refs more than one table */
- for(i=0; mPrereq>1; i++, mPrereq>>=1){}
- iCur = pFrom->a[i].iCursor;
- for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
- if( pIdx->aColExpr==0 ) continue;
- for(i=0; i<pIdx->nKeyCol; i++){
- if( pIdx->aiColumn[i]!=(-2) ) continue;
- if( sqlite3ExprCompare(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
- *piCur = iCur;
- *piColumn = -2;
- return 1;
- }
- }
- }
- return 0;
-}
-
-/*
-** The input to this routine is an WhereTerm structure with only the
-** "pExpr" field filled in. The job of this routine is to analyze the
-** subexpression and populate all the other fields of the WhereTerm
-** structure.
-**
-** If the expression is of the form "<expr> <op> X" it gets commuted
-** to the standard form of "X <op> <expr>".
-**
-** If the expression is of the form "X <op> Y" where both X and Y are
-** columns, then the original expression is unchanged and a new virtual
-** term of the form "Y <op> X" is added to the WHERE clause and
-** analyzed separately. The original term is marked with TERM_COPIED
-** and the new term is marked with TERM_DYNAMIC (because it's pExpr
-** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it
-** is a commuted copy of a prior term.) The original term has nChild=1
-** and the copy has idxParent set to the index of the original term.
-*/
-static void exprAnalyze(
- SrcList *pSrc, /* the FROM clause */
- WhereClause *pWC, /* the WHERE clause */
- int idxTerm /* Index of the term to be analyzed */
-){
- WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
- WhereTerm *pTerm; /* The term to be analyzed */
- WhereMaskSet *pMaskSet; /* Set of table index masks */
- Expr *pExpr; /* The expression to be analyzed */
- Bitmask prereqLeft; /* Prerequesites of the pExpr->pLeft */
- Bitmask prereqAll; /* Prerequesites of pExpr */
- Bitmask extraRight = 0; /* Extra dependencies on LEFT JOIN */
- Expr *pStr1 = 0; /* RHS of LIKE/GLOB operator */
- int isComplete = 0; /* RHS of LIKE/GLOB ends with wildcard */
- int noCase = 0; /* uppercase equivalent to lowercase */
- int op; /* Top-level operator. pExpr->op */
- Parse *pParse = pWInfo->pParse; /* Parsing context */
- sqlite3 *db = pParse->db; /* Database connection */
- unsigned char eOp2; /* op2 value for LIKE/REGEXP/GLOB */
-
- if( db->mallocFailed ){
- return;
- }
- pTerm = &pWC->a[idxTerm];
- pMaskSet = &pWInfo->sMaskSet;
- pExpr = pTerm->pExpr;
- assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
- prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
- op = pExpr->op;
- if( op==TK_IN ){
- assert( pExpr->pRight==0 );
- if( ExprHasProperty(pExpr, EP_xIsSelect) ){
- pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
- }else{
- pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
- }
- }else if( op==TK_ISNULL ){
- pTerm->prereqRight = 0;
- }else{
- pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
- }
- prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr);
- if( ExprHasProperty(pExpr, EP_FromJoin) ){
- Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
- prereqAll |= x;
- extraRight = x-1; /* ON clause terms may not be used with an index
- ** on left table of a LEFT JOIN. Ticket #3015 */
- }
- pTerm->prereqAll = prereqAll;
- pTerm->leftCursor = -1;
- pTerm->iParent = -1;
- pTerm->eOperator = 0;
- if( allowedOp(op) ){
- int iCur, iColumn;
- Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
- Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
- u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
- if( exprMightBeIndexed(pSrc, prereqLeft, pLeft, &iCur, &iColumn) ){
- pTerm->leftCursor = iCur;
- pTerm->u.leftColumn = iColumn;
- pTerm->eOperator = operatorMask(op) & opMask;
- }
- if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
- if( pRight
- && exprMightBeIndexed(pSrc, pTerm->prereqRight, pRight, &iCur, &iColumn)
- ){
- WhereTerm *pNew;
- Expr *pDup;
- u16 eExtraOp = 0; /* Extra bits for pNew->eOperator */
- if( pTerm->leftCursor>=0 ){
- int idxNew;
- pDup = sqlite3ExprDup(db, pExpr, 0);
- if( db->mallocFailed ){
- sqlite3ExprDelete(db, pDup);
- return;
- }
- idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
- if( idxNew==0 ) return;
- pNew = &pWC->a[idxNew];
- markTermAsChild(pWC, idxNew, idxTerm);
- if( op==TK_IS ) pNew->wtFlags |= TERM_IS;
- pTerm = &pWC->a[idxTerm];
- pTerm->wtFlags |= TERM_COPIED;
-
- if( termIsEquivalence(pParse, pDup) ){
- pTerm->eOperator |= WO_EQUIV;
- eExtraOp = WO_EQUIV;
- }
- }else{
- pDup = pExpr;
- pNew = pTerm;
- }
- exprCommute(pParse, pDup);
- pNew->leftCursor = iCur;
- pNew->u.leftColumn = iColumn;
- testcase( (prereqLeft | extraRight) != prereqLeft );
- pNew->prereqRight = prereqLeft | extraRight;
- pNew->prereqAll = prereqAll;
- pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
- }
- }
-
-#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
- /* If a term is the BETWEEN operator, create two new virtual terms
- ** that define the range that the BETWEEN implements. For example:
- **
- ** a BETWEEN b AND c
- **
- ** is converted into:
- **
- ** (a BETWEEN b AND c) AND (a>=b) AND (a<=c)
- **
- ** The two new terms are added onto the end of the WhereClause object.
- ** The new terms are "dynamic" and are children of the original BETWEEN
- ** term. That means that if the BETWEEN term is coded, the children are
- ** skipped. Or, if the children are satisfied by an index, the original
- ** BETWEEN term is skipped.
- */
- else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){
- ExprList *pList = pExpr->x.pList;
- int i;
- static const u8 ops[] = {TK_GE, TK_LE};
- assert( pList!=0 );
- assert( pList->nExpr==2 );
- for(i=0; i<2; i++){
- Expr *pNewExpr;
- int idxNew;
- pNewExpr = sqlite3PExpr(pParse, ops[i],
- sqlite3ExprDup(db, pExpr->pLeft, 0),
- sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
- transferJoinMarkings(pNewExpr, pExpr);
- idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
- testcase( idxNew==0 );
- exprAnalyze(pSrc, pWC, idxNew);
- pTerm = &pWC->a[idxTerm];
- markTermAsChild(pWC, idxNew, idxTerm);
- }
- }
-#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
-
-#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
- /* Analyze a term that is composed of two or more subterms connected by
- ** an OR operator.
- */
- else if( pExpr->op==TK_OR ){
- assert( pWC->op==TK_AND );
- exprAnalyzeOrTerm(pSrc, pWC, idxTerm);
- pTerm = &pWC->a[idxTerm];
- }
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
-
-#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
- /* Add constraints to reduce the search space on a LIKE or GLOB
- ** operator.
- **
- ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints
- **
- ** x>='ABC' AND x<'abd' AND x LIKE 'aBc%'
- **
- ** The last character of the prefix "abc" is incremented to form the
- ** termination condition "abd". If case is not significant (the default
- ** for LIKE) then the lower-bound is made all uppercase and the upper-
- ** bound is made all lowercase so that the bounds also work when comparing
- ** BLOBs.
- */
- if( pWC->op==TK_AND
- && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
- ){
- Expr *pLeft; /* LHS of LIKE/GLOB operator */
- Expr *pStr2; /* Copy of pStr1 - RHS of LIKE/GLOB operator */
- Expr *pNewExpr1;
- Expr *pNewExpr2;
- int idxNew1;
- int idxNew2;
- const char *zCollSeqName; /* Name of collating sequence */
- const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;
-
- pLeft = pExpr->x.pList->a[1].pExpr;
- pStr2 = sqlite3ExprDup(db, pStr1, 0);
-
- /* Convert the lower bound to upper-case and the upper bound to
- ** lower-case (upper-case is less than lower-case in ASCII) so that
- ** the range constraints also work for BLOBs
- */
- if( noCase && !pParse->db->mallocFailed ){
- int i;
- char c;
- pTerm->wtFlags |= TERM_LIKE;
- for(i=0; (c = pStr1->u.zToken[i])!=0; i++){
- pStr1->u.zToken[i] = sqlite3Toupper(c);
- pStr2->u.zToken[i] = sqlite3Tolower(c);
- }
- }
-
- if( !db->mallocFailed ){
- u8 c, *pC; /* Last character before the first wildcard */
- pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
- c = *pC;
- if( noCase ){
- /* The point is to increment the last character before the first
- ** wildcard. But if we increment '@', that will push it into the
- ** alphabetic range where case conversions will mess up the
- ** inequality. To avoid this, make sure to also run the full
- ** LIKE on all candidate expressions by clearing the isComplete flag
- */
- if( c=='A'-1 ) isComplete = 0;
- c = sqlite3UpperToLower[c];
- }
- *pC = c + 1;
- }
- zCollSeqName = noCase ? "NOCASE" : "BINARY";
- pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
- pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
- sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
- pStr1, 0);
- transferJoinMarkings(pNewExpr1, pExpr);
- idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
- testcase( idxNew1==0 );
- exprAnalyze(pSrc, pWC, idxNew1);
- pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
- pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
- sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),
- pStr2, 0);
- transferJoinMarkings(pNewExpr2, pExpr);
- idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);
- testcase( idxNew2==0 );
- exprAnalyze(pSrc, pWC, idxNew2);
- pTerm = &pWC->a[idxTerm];
- if( isComplete ){
- markTermAsChild(pWC, idxNew1, idxTerm);
- markTermAsChild(pWC, idxNew2, idxTerm);
- }
- }
-#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
-
-#ifndef SQLITE_OMIT_VIRTUALTABLE
- /* Add a WO_MATCH auxiliary term to the constraint set if the
- ** current expression is of the form: column MATCH expr.
- ** This information is used by the xBestIndex methods of
- ** virtual tables. The native query optimizer does not attempt
- ** to do anything with MATCH functions.
- */
- if( isMatchOfColumn(pExpr, &eOp2) ){
- int idxNew;
- Expr *pRight, *pLeft;
- WhereTerm *pNewTerm;
- Bitmask prereqColumn, prereqExpr;
-
- pRight = pExpr->x.pList->a[0].pExpr;
- pLeft = pExpr->x.pList->a[1].pExpr;
- prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
- prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
- if( (prereqExpr & prereqColumn)==0 ){
- Expr *pNewExpr;
- pNewExpr = sqlite3PExpr(pParse, TK_MATCH,
- 0, sqlite3ExprDup(db, pRight, 0), 0);
- idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
- testcase( idxNew==0 );
- pNewTerm = &pWC->a[idxNew];
- pNewTerm->prereqRight = prereqExpr;
- pNewTerm->leftCursor = pLeft->iTable;
- pNewTerm->u.leftColumn = pLeft->iColumn;
- pNewTerm->eOperator = WO_MATCH;
- pNewTerm->eMatchOp = eOp2;
- markTermAsChild(pWC, idxNew, idxTerm);
- pTerm = &pWC->a[idxTerm];
- pTerm->wtFlags |= TERM_COPIED;
- pNewTerm->prereqAll = pTerm->prereqAll;
- }
- }
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
-#ifdef SQLITE_ENABLE_STAT3_OR_STAT4
- /* When sqlite_stat3 histogram data is available an operator of the
- ** form "x IS NOT NULL" can sometimes be evaluated more efficiently
- ** as "x>NULL" if x is not an INTEGER PRIMARY KEY. So construct a
- ** virtual term of that form.
- **
- ** Note that the virtual term must be tagged with TERM_VNULL.
- */
- if( pExpr->op==TK_NOTNULL
- && pExpr->pLeft->op==TK_COLUMN
- && pExpr->pLeft->iColumn>=0
- && OptimizationEnabled(db, SQLITE_Stat34)
- ){
- Expr *pNewExpr;
- Expr *pLeft = pExpr->pLeft;
- int idxNew;
- WhereTerm *pNewTerm;
-
- pNewExpr = sqlite3PExpr(pParse, TK_GT,
- sqlite3ExprDup(db, pLeft, 0),
- sqlite3PExpr(pParse, TK_NULL, 0, 0, 0), 0);
-
- idxNew = whereClauseInsert(pWC, pNewExpr,
- TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
- if( idxNew ){
- pNewTerm = &pWC->a[idxNew];
- pNewTerm->prereqRight = 0;
- pNewTerm->leftCursor = pLeft->iTable;
- pNewTerm->u.leftColumn = pLeft->iColumn;
- pNewTerm->eOperator = WO_GT;
- markTermAsChild(pWC, idxNew, idxTerm);
- pTerm = &pWC->a[idxTerm];
- pTerm->wtFlags |= TERM_COPIED;
- pNewTerm->prereqAll = pTerm->prereqAll;
- }
- }
-#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */
-
- /* Prevent ON clause terms of a LEFT JOIN from being used to drive
- ** an index for tables to the left of the join.
- */
- pTerm->prereqRight |= extraRight;
-}
-
-/***************************************************************************
-** Routines with file scope above. Interface to the rest of the where.c
-** subsystem follows.
-***************************************************************************/
-
-/*
-** This routine identifies subexpressions in the WHERE clause where
-** each subexpression is separated by the AND operator or some other
-** operator specified in the op parameter. The WhereClause structure
-** is filled with pointers to subexpressions. For example:
-**
-** WHERE a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
-** \________/ \_______________/ \________________/
-** slot[0] slot[1] slot[2]
-**
-** The original WHERE clause in pExpr is unaltered. All this routine
-** does is make slot[] entries point to substructure within pExpr.
-**
-** In the previous sentence and in the diagram, "slot[]" refers to
-** the WhereClause.a[] array. The slot[] array grows as needed to contain
-** all terms of the WHERE clause.
-*/
-void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
- Expr *pE2 = sqlite3ExprSkipCollate(pExpr);
- pWC->op = op;
- if( pE2==0 ) return;
- if( pE2->op!=op ){
- whereClauseInsert(pWC, pExpr, 0);
- }else{
- sqlite3WhereSplit(pWC, pE2->pLeft, op);
- sqlite3WhereSplit(pWC, pE2->pRight, op);
- }
-}
-
-/*
-** Initialize a preallocated WhereClause structure.
-*/
-void sqlite3WhereClauseInit(
- WhereClause *pWC, /* The WhereClause to be initialized */
- WhereInfo *pWInfo /* The WHERE processing context */
-){
- pWC->pWInfo = pWInfo;
- pWC->pOuter = 0;
- pWC->nTerm = 0;
- pWC->nSlot = ArraySize(pWC->aStatic);
- pWC->a = pWC->aStatic;
-}
-
-/*
-** Deallocate a WhereClause structure. The WhereClause structure
-** itself is not freed. This routine is the inverse of
-** sqlite3WhereClauseInit().
-*/
-void sqlite3WhereClauseClear(WhereClause *pWC){
- int i;
- WhereTerm *a;
- sqlite3 *db = pWC->pWInfo->pParse->db;
- for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
- if( a->wtFlags & TERM_DYNAMIC ){
- sqlite3ExprDelete(db, a->pExpr);
- }
- if( a->wtFlags & TERM_ORINFO ){
- whereOrInfoDelete(db, a->u.pOrInfo);
- }else if( a->wtFlags & TERM_ANDINFO ){
- whereAndInfoDelete(db, a->u.pAndInfo);
- }
- }
- if( pWC->a!=pWC->aStatic ){
- sqlite3DbFree(db, pWC->a);
- }
-}
-
-
-/*
-** These routines walk (recursively) an expression tree and generate
-** a bitmask indicating which tables are used in that expression
-** tree.
-*/
-Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
- Bitmask mask = 0;
- if( p==0 ) return 0;
- if( p->op==TK_COLUMN ){
- mask = sqlite3WhereGetMask(pMaskSet, p->iTable);
- return mask;
- }
- mask = sqlite3WhereExprUsage(pMaskSet, p->pRight);
- mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
- if( ExprHasProperty(p, EP_xIsSelect) ){
- mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
- }else{
- mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
- }
- return mask;
-}
-Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
- int i;
- Bitmask mask = 0;
- if( pList ){
- for(i=0; i<pList->nExpr; i++){
- mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
- }
- }
- return mask;
-}
-
-
-/*
-** Call exprAnalyze on all terms in a WHERE clause.
-**
-** Note that exprAnalyze() might add new virtual terms onto the
-** end of the WHERE clause. We do not want to analyze these new
-** virtual terms, so start analyzing at the end and work forward
-** so that the added virtual terms are never processed.
-*/
-void sqlite3WhereExprAnalyze(
- SrcList *pTabList, /* the FROM clause */
- WhereClause *pWC /* the WHERE clause to be analyzed */
-){
- int i;
- for(i=pWC->nTerm-1; i>=0; i--){
- exprAnalyze(pTabList, pWC, i);
- }
-}
-
-/*
-** For table-valued-functions, transform the function arguments into
-** new WHERE clause terms.
-**
-** Each function argument translates into an equality constraint against
-** a HIDDEN column in the table.
-*/
-void sqlite3WhereTabFuncArgs(
- Parse *pParse, /* Parsing context */
- struct SrcList_item *pItem, /* The FROM clause term to process */
- WhereClause *pWC /* Xfer function arguments to here */
-){
- Table *pTab;
- int j, k;
- ExprList *pArgs;
- Expr *pColRef;
- Expr *pTerm;
- if( pItem->fg.isTabFunc==0 ) return;
- pTab = pItem->pTab;
- assert( pTab!=0 );
- pArgs = pItem->u1.pFuncArg;
- if( pArgs==0 ) return;
- for(j=k=0; j<pArgs->nExpr; j++){
- while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
- if( k>=pTab->nCol ){
- sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
- pTab->zName, j);
- return;
- }
- pColRef = sqlite3PExpr(pParse, TK_COLUMN, 0, 0, 0);
- if( pColRef==0 ) return;
- pColRef->iTable = pItem->iCursor;
- pColRef->iColumn = k++;
- pColRef->pTab = pTab;
- pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef,
- sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
- whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
- }
-}
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