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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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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | multikey-opt-idea |
| Files: | files | file ages | folders |
| SHA3-256: |
87a9fc504f9a78caf7a7949cc7ada0a1 |
| User & Date: | drh 2018-06-05 15:16:25 |
Context
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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: 6bf251af 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: 87a9fc50 user: drh tags: multikey-opt-idea | |
| 13:54 | Merge trunk changes. check-in: 047295c5 user: drh tags: multikey-opt-idea | |
Changes
Changes to src/where.c.
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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 ){
sqlite3VdbeAddOp3(v, OP_Noop, pLevel->iIdxCur,
pIn->iBase, pIn->nPrefix);
}
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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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);
|
Changes to src/wherecode.c.
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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;
pIn->iBase = iReg - i;
pIn->nPrefix = i;
}else{
pIn->eEndLoopOp = OP_Noop;
}
pIn++;
}
}
}else{
|
> | | > > > |
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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{
|