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Overview
Comment: | Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop. |
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Timelines: | family | ancestors | descendants | both | multikey-opt-idea |
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SHA3-256: |
87a9fc504f9a78caf7a7949cc7ada0a1 |
User & Date: | drh 2018-06-05 15:16:25.289 |
Context
2018-06-05
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20:45 | Add the OP_IfNoHope and OP_SeekHit opcodes used to reduce the number of unnecessary sqlite3BtreeMovetoUnpacked() calls when checking for an early exit on IN-operator loops. Futher optimizations are likely possible here. (check-in: 6bf251af43 user: drh tags: multikey-opt-idea) | |
15:16 | Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop. (check-in: 87a9fc504f user: drh tags: multikey-opt-idea) | |
13:54 | Merge trunk changes. (check-in: 047295c588 user: drh tags: multikey-opt-idea) | |
Changes
Changes to src/where.c.
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5080 5081 5082 5083 5084 5085 5086 | struct InLoop *pIn; int j; sqlite3VdbeResolveLabel(v, pLevel->addrNxt); for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){ sqlite3VdbeJumpHere(v, pIn->addrInTop+1); if( pIn->eEndLoopOp!=OP_Noop ){ if( pIn->nPrefix ){ | | > > | 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 | struct InLoop *pIn; int j; sqlite3VdbeResolveLabel(v, pLevel->addrNxt); for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){ sqlite3VdbeJumpHere(v, pIn->addrInTop+1); if( pIn->eEndLoopOp!=OP_Noop ){ if( pIn->nPrefix ){ sqlite3VdbeAddOp4Int(v, OP_NotFound, pLevel->iIdxCur, sqlite3VdbeCurrentAddr(v)+2, pIn->iBase, pIn->nPrefix); VdbeCoverage(v); } sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop); VdbeCoverage(v); VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen); VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen); } sqlite3VdbeJumpHere(v, pIn->addrInTop-1); |
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Changes to src/wherecode.c.
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588 589 590 591 592 593 594 | int iCol = aiMap ? aiMap[iMap++] : 0; pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut); } sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v); if( i==iEq ){ pIn->iCur = iTab; pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen; | > | | > > > | 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 | int iCol = aiMap ? aiMap[iMap++] : 0; pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut); } sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v); if( i==iEq ){ pIn->iCur = iTab; pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen; if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ){ pIn->iBase = iReg - i; pIn->nPrefix = i; }else{ pIn->nPrefix = 0; } }else{ pIn->eEndLoopOp = OP_Noop; } pIn++; } } }else{ |
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