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Overview
| Comment: | Improvements to the min()/max() optimization so that it is able to use indexes where terms are constrained by IN operators. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
b8ba2f17f938c03543a89dd29d698716 |
| User & Date: | drh 2020-07-14 23:58:04 |
References
|
2021-01-14
| ||
| 20:57 | Improvements to the min/max optimization. Fix for a performance regression introduced at [b8ba2f17f938c035] reported by forum post 4050026ab8 (check-in: 249a71cc user: drh tags: trunk) | |
|
2021-01-13
| ||
| 15:23 | Further enhancements to the min/max optimization of check-in b8ba2f17f938c035 to fix the performance regression identified by forum post 4050026ab8. (check-in: 188772a1 user: drh tags: minmax-opt-exp) | |
Context
|
2020-07-15
| ||
| 02:15 | New test cases for decimal and ieee754. (check-in: 73d62f82 user: drh tags: trunk) | |
|
2020-07-14
| ||
| 23:58 | Improvements to the min()/max() optimization so that it is able to use indexes where terms are constrained by IN operators. (check-in: b8ba2f17 user: drh tags: trunk) | |
| 22:20 | Now appears to work. All legacy tests pass. Need to add new tests, however. (Closed-Leaf check-in: 81e64509 user: drh tags: minmax-opt-exp) | |
| 15:30 | Fix an obsolete header comment on the sqlite3WhereIsOrdered() routine. (check-in: 5041f6a1 user: drh tags: trunk) | |
Changes
Changes to src/select.c.
| ︙ | ︙ | |||
6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713 6714 6715 |
sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
}
sqlite3VdbeAddOp2(v, OP_Count, iCsr, pAggInfo->aFunc[0].iMem);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
explainSimpleCount(pParse, pTab, pBest);
}else{
int regAcc = 0; /* "populate accumulators" flag */
/* If there are accumulator registers but no min() or max() functions
** without FILTER clauses, allocate register regAcc. Register regAcc
** will contain 0 the first time the inner loop runs, and 1 thereafter.
** The code generated by updateAccumulator() uses this to ensure
** that the accumulator registers are (a) updated only once if
** there are no min() or max functions or (b) always updated for the
| > | 6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713 6714 6715 6716 |
sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
}
sqlite3VdbeAddOp2(v, OP_Count, iCsr, pAggInfo->aFunc[0].iMem);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
explainSimpleCount(pParse, pTab, pBest);
}else{
int regAcc = 0; /* "populate accumulators" flag */
int addrSkip;
/* If there are accumulator registers but no min() or max() functions
** without FILTER clauses, allocate register regAcc. Register regAcc
** will contain 0 the first time the inner loop runs, and 1 thereafter.
** The code generated by updateAccumulator() uses this to ensure
** that the accumulator registers are (a) updated only once if
** there are no min() or max functions or (b) always updated for the
|
| ︙ | ︙ | |||
6750 6751 6752 6753 6754 6755 6756 |
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
0, minMaxFlag, 0);
if( pWInfo==0 ){
goto select_end;
}
updateAccumulator(pParse, regAcc, pAggInfo);
if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);
| | > | < < | 6751 6752 6753 6754 6755 6756 6757 6758 6759 6760 6761 6762 6763 6764 6765 6766 6767 |
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
0, minMaxFlag, 0);
if( pWInfo==0 ){
goto select_end;
}
updateAccumulator(pParse, regAcc, pAggInfo);
if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);
addrSkip = sqlite3WhereOrderByLimitOptLabel(pWInfo);
if( addrSkip!=sqlite3WhereContinueLabel(pWInfo) ){
sqlite3VdbeGoto(v, addrSkip);
}
sqlite3WhereEnd(pWInfo);
finalizeAggFunctions(pParse, pAggInfo);
}
sSort.pOrderBy = 0;
sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
|
| ︙ | ︙ |
Changes to src/where.c.
| ︙ | ︙ | |||
3740 3741 3742 3743 3744 3745 3746 | testcase( nOrderBy==BMS-1 ); if( nOrderBy>BMS-1 ) return 0; /* Cannot optimize overly large ORDER BYs */ isOrderDistinct = 1; obDone = MASKBIT(nOrderBy)-1; orderDistinctMask = 0; ready = 0; eqOpMask = WO_EQ | WO_IS | WO_ISNULL; | > | > | 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 |
testcase( nOrderBy==BMS-1 );
if( nOrderBy>BMS-1 ) return 0; /* Cannot optimize overly large ORDER BYs */
isOrderDistinct = 1;
obDone = MASKBIT(nOrderBy)-1;
orderDistinctMask = 0;
ready = 0;
eqOpMask = WO_EQ | WO_IS | WO_ISNULL;
if( wctrlFlags & (WHERE_ORDERBY_LIMIT|WHERE_ORDERBY_MAX|WHERE_ORDERBY_MIN) ){
eqOpMask |= WO_IN;
}
for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
if( iLoop>0 ) ready |= pLoop->maskSelf;
if( iLoop<nLoop ){
pLoop = pPath->aLoop[iLoop];
if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
}else{
pLoop = pLast;
|
| ︙ | ︙ | |||
3776 3777 3778 3779 3780 3781 3782 |
pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
~ready, eqOpMask, 0);
if( pTerm==0 ) continue;
if( pTerm->eOperator==WO_IN ){
/* IN terms are only valid for sorting in the ORDER BY LIMIT
** optimization, and then only if they are actually used
** by the query plan */
| | > | 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 |
pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
~ready, eqOpMask, 0);
if( pTerm==0 ) continue;
if( pTerm->eOperator==WO_IN ){
/* IN terms are only valid for sorting in the ORDER BY LIMIT
** optimization, and then only if they are actually used
** by the query plan */
assert( wctrlFlags &
(WHERE_ORDERBY_LIMIT|WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) );
for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
if( j>=pLoop->nLTerm ) continue;
}
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
Parse *pParse = pWInfo->pParse;
CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pOrderBy->a[i].pExpr);
CollSeq *pColl2 = sqlite3ExprCompareCollSeq(pParse, pTerm->pExpr);
|
| ︙ | ︙ | |||
4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 |
testcase( wsFlags & WHERE_COLUMN_IN );
if( rc==pWInfo->pOrderBy->nExpr ){
pWInfo->bOrderedInnerLoop = 1;
pWInfo->revMask = m;
}
}
}
}
}
if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
&& pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
){
Bitmask revMask = 0;
int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy,
| > > > > > | 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 |
testcase( wsFlags & WHERE_COLUMN_IN );
if( rc==pWInfo->pOrderBy->nExpr ){
pWInfo->bOrderedInnerLoop = 1;
pWInfo->revMask = m;
}
}
}
}else if( nLoop
&& pWInfo->nOBSat==1
&& (pWInfo->wctrlFlags & (WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX))!=0
){
pWInfo->bOrderedInnerLoop = 1;
}
}
if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP)
&& pWInfo->nOBSat==pWInfo->pOrderBy->nExpr && nLoop>0
){
Bitmask revMask = 0;
int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy,
|
| ︙ | ︙ |