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Aggregates with GROUP BY now make use of expressions on indexes. This code

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works and gets the correct answer for the test case in the ticket.  Lots more
testing and documentation is needed, however.

FossilOrigin-Name: 8dcf9f2031c16f296d187fe876d4204c71fc96fec120984ff11b6d8b03d58a5f
This commit is contained in:
drh
2022-11-23 18:51:04 +00:00
parent 590f013a87
commit 2e30d95fb6
4 changed files with 59 additions and 11 deletions
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48
src/select.c
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@@ -6222,7 +6222,7 @@ static void printAggInfo(AggInfo *pAggInfo){
sqlite3TreeViewExpr(0, pAggInfo->aCol[ii].pCExpr, 0);
}
for(ii=0; ii<pAggInfo->nFunc; ii++){
sqlite3DebugPrintf("agg-func[%d]: iMem=\n",
sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
ii, AggInfoFuncReg(pAggInfo,ii));
sqlite3TreeViewExpr(0, pAggInfo->aFunc[ii].pFExpr, 0);
}
@@ -6309,6 +6309,40 @@ static void optimizeAggregateUseOfIndexedExpr(
#endif
}
/*
** Walker callback for aggregateConvertIndexedExprRefToColumn().
*/
static int aggregateIdxEprRefToColCallback(Walker *pWalker, Expr *pExpr){
AggInfo *pAggInfo;
struct AggInfo_col *pCol;
if( pExpr->pAggInfo==0 ) return WRC_Continue;
if( pExpr->op==TK_AGG_COLUMN ) return WRC_Continue;
if( pExpr->op==TK_AGG_FUNCTION ) return WRC_Continue;
pAggInfo = pExpr->pAggInfo;
assert( pExpr->iAgg>=0 && pExpr->iAgg<pAggInfo->nColumn );
pCol = &pAggInfo->aCol[pExpr->iAgg];
pExpr->op = TK_AGG_COLUMN;
pExpr->iTable = pCol->iTable;
pExpr->iColumn = pCol->iColumn;
return WRC_Prune;
}
/*
** Convert every pAggInfo->aFunc[].pExpr such that any node within
** those expressions that has pAppInfo set is changed into a TK_AGG_COLUMN
** opcode.
*/
static void aggregateConvertIndexedExprRefToColumn(AggInfo *pAggInfo){
int i;
Walker w;
memset(&w, 0, sizeof(w));
w.xExprCallback = aggregateIdxEprRefToColCallback;
for(i=0; i<pAggInfo->nFunc; i++){
sqlite3WalkExpr(&w, pAggInfo->aFunc[i].pFExpr);
}
}
/*
** Allocate a block of registers so that there is one register for each
** pAggInfo->aCol[] and pAggInfo->aFunc[] entry in pAggInfo. The first
@@ -7669,6 +7703,18 @@ int sqlite3Select(
pAggInfo->useSortingIdx = 1;
}
if( pParse->pIdxEpr ){
aggregateConvertIndexedExprRefToColumn(pAggInfo);
#if TREETRACE_ENABLED
if( sqlite3TreeTrace & 0x20 ){
TREETRACE(0x20, pParse, p,
("AggInfo function expressions converted to reference index\n"));
sqlite3TreeViewSelect(0, p, 0);
printAggInfo(pAggInfo);
}
#endif
}
/* If the index or temporary table used by the GROUP BY sort
** will naturally deliver rows in the order required by the ORDER BY
** clause, cancel the ephemeral table open coded earlier.