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Always use LIKE optimization range constraints in pairs.

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FossilOrigin-Name: 0e02dc94fd1bb891d0edd1e34b57e923b17712a7
This commit is contained in:
drh
2015-03-09 12:11:56 +00:00
parent 52fc05ba1c
commit a40da62dd4
3 changed files with 35 additions and 20 deletions
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38
src/where.c
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@@ -3013,8 +3013,8 @@ static void addScanStatus(
#endif
/*
** Look at the last instruction coded. If that instruction is OP_String8
** and if pLoop->iLikeRepCntr is non-zero, then change the P3 to be
** If the most recently coded instruction is a constant range contraint
** that originated from the LIKE optimization, then change the P3 to be
** pLoop->iLikeRepCntr and set P5.
**
** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
@@ -3030,11 +3030,14 @@ static void whereLikeOptimizationStringFixup(
WhereTerm *pTerm /* The upper or lower bound just coded */
){
if( pTerm->wtFlags & TERM_LIKEOPT ){
VdbeOp *pOp = sqlite3VdbeGetOp(v, -1);
if( pLevel->iLikeRepCntr && pOp->opcode==OP_String8 ){
pOp->p3 = pLevel->iLikeRepCntr;
pOp->p5 = 1;
}
VdbeOp *pOp;
assert( pLevel->iLikeRepCntr>0 );
pOp = sqlite3VdbeGetOp(v, -1);
assert( pOp!=0 );
assert( pOp->opcode==OP_String8
|| pTerm->pWC->pWInfo->pParse->db->mallocFailed );
pOp->p3 = pLevel->iLikeRepCntr;
pOp->p5 = 1;
}
}
@@ -3370,9 +3373,9 @@ static Bitmask codeOneLoopStart(
if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
pRangeEnd = pLoop->aLTerm[j++];
nExtraReg = 1;
if( (pRangeStart && (pRangeStart->wtFlags & TERM_LIKEOPT)!=0)
|| (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0
){
if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
assert( pRangeStart!=0 );
assert( pRangeStart->wtFlags & TERM_LIKEOPT );
pLevel->iLikeRepCntr = ++pParse->nMem;
testcase( bRev );
testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
@@ -4547,6 +4550,10 @@ static int whereLoopAddBtreeIndex(
}
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;
@@ -4590,6 +4597,17 @@ static int whereLoopAddBtreeIndex(
pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
pBtm = pTerm;
pTop = 0;
if( pTerm->wtFlags & TERM_LIKEOPT ){
/* Make sure that 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 );