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Overview
Comment: | Always use LIKE optimization range constraints in pairs. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | like-opt-fix |
Files: | files | file ages | folders |
SHA1: |
0e02dc94fd1bb891d0edd1e34b57e923 |
User & Date: | drh 2015-03-09 12:11:56.889 |
Context
2015-03-09
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13:01 | Fix the LIKE optimization so that it works even if there are additional range contraints on the column that is subject to the LIKE or GLOB. (check-in: 984c3fd526 user: drh tags: trunk) | |
12:11 | Always use LIKE optimization range constraints in pairs. (Closed-Leaf check-in: 0e02dc94fd user: drh tags: like-opt-fix) | |
2015-03-07
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20:32 | Fix another problem with the LIKE optimization. (check-in: 465bfc72d2 user: drh tags: like-opt-fix) | |
Changes
Changes to src/where.c.
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3009 3010 3011 3012 3013 3014 3015 | ); } #else # define addScanStatus(a, b, c, d) ((void)d) #endif /* | | | > > | > | > | | < | 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 | ); } #else # define addScanStatus(a, b, c, d) ((void)d) #endif /* ** If the most recently coded instruction is a constant range contraint ** that originated from the LIKE optimization, then change the P3 to be ** pLoop->iLikeRepCntr and set P5. ** ** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range ** expression: "x>='ABC' AND x<'abd'". But this requires that the range ** scan loop run twice, once for strings and a second time for BLOBs. ** The OP_String opcodes on the second pass convert the upper and lower ** bound string contants to blobs. This routine makes the necessary changes ** to the OP_String opcodes for that to happen. */ static void whereLikeOptimizationStringFixup( Vdbe *v, /* prepared statement under construction */ WhereLevel *pLevel, /* The loop that contains the LIKE operator */ WhereTerm *pTerm /* The upper or lower bound just coded */ ){ if( pTerm->wtFlags & TERM_LIKEOPT ){ VdbeOp *pOp; assert( pLevel->iLikeRepCntr>0 ); pOp = sqlite3VdbeGetOp(v, -1); assert( pOp!=0 ); assert( pOp->opcode==OP_String8 || pTerm->pWC->pWInfo->pParse->db->mallocFailed ); pOp->p3 = pLevel->iLikeRepCntr; pOp->p5 = 1; } } /* ** Generate code for the start of the iLevel-th loop in the WHERE clause ** implementation described by pWInfo. */ |
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3366 3367 3368 3369 3370 3371 3372 | if( pLoop->wsFlags & WHERE_BTM_LIMIT ){ pRangeStart = pLoop->aLTerm[j++]; nExtraReg = 1; } if( pLoop->wsFlags & WHERE_TOP_LIMIT ){ pRangeEnd = pLoop->aLTerm[j++]; nExtraReg = 1; | | > | < | 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 | 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( (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 ); sqlite3VdbeAddOp2(v, OP_Integer, bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC), pLevel->iLikeRepCntr); VdbeComment((v, "LIKE loop counter")); |
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4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 | if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0) && (iCol<0 || pSrc->pTab->aCol[iCol].notNull) ){ continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */ } if( pTerm->prereqRight & pNew->maskSelf ) continue; pNew->wsFlags = saved_wsFlags; pNew->u.btree.nEq = saved_nEq; pNew->nLTerm = saved_nLTerm; if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */ pNew->aLTerm[pNew->nLTerm++] = pTerm; pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf; | > > > > | 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 | if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0) && (iCol<0 || pSrc->pTab->aCol[iCol].notNull) ){ continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */ } if( pTerm->prereqRight & pNew->maskSelf ) continue; /* Do not allow the upper bound of a LIKE optimization range constraint ** to mix with a lower range bound from some other source */ if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue; pNew->wsFlags = saved_wsFlags; pNew->u.btree.nEq = saved_nEq; pNew->nLTerm = saved_nLTerm; if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */ pNew->aLTerm[pNew->nLTerm++] = pTerm; pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf; |
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4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 | pNew->wsFlags |= WHERE_COLUMN_NULL; }else if( eOp & (WO_GT|WO_GE) ){ testcase( eOp & WO_GT ); testcase( eOp & WO_GE ); pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT; pBtm = pTerm; pTop = 0; }else{ assert( eOp & (WO_LT|WO_LE) ); testcase( eOp & WO_LT ); testcase( eOp & WO_LE ); pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT; pTop = pTerm; pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ? | > > > > > > > > > > > | 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603 4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 | pNew->wsFlags |= WHERE_COLUMN_NULL; }else if( eOp & (WO_GT|WO_GE) ){ testcase( eOp & WO_GT ); testcase( eOp & WO_GE ); pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT; pBtm = pTerm; pTop = 0; if( pTerm->wtFlags & TERM_LIKEOPT ){ /* 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 ); testcase( eOp & WO_LE ); pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT; pTop = pTerm; pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ? |
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