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When optimizing expressions of the form "x IN (SELECT ...)" make sure that

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the subquery is not correlated.  Fix for ticket [5e3c886796e5512].

FossilOrigin-Name: 1ed6b06ea3c432f920fb2b66b6042be906c5d21c
This commit is contained in:
drh
2016-03-09 15:09:22 +00:00
parent 7c621fb967
commit 90730c9e68
4 changed files with 23 additions and 9 deletions
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5
src/expr.c
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@@ -1584,6 +1584,7 @@ static int isCandidateForInOpt(Select *p){
SrcList *pSrc;
ExprList *pEList;
Table *pTab;
Expr *pRes; /* Result expression */
if( p==0 ) return 0; /* right-hand side of IN is SELECT */
if( p->pPrior ) return 0; /* Not a compound SELECT */
if( p->selFlags & (SF_Distinct|SF_Aggregate) ){
@@ -1605,7 +1606,9 @@ static int isCandidateForInOpt(Select *p){
if( IsVirtual(pTab) ) return 0; /* FROM clause not a virtual table */
pEList = p->pEList;
if( pEList->nExpr!=1 ) return 0; /* One column in the result set */
if( pEList->a[0].pExpr->op!=TK_COLUMN ) return 0; /* Result is a column */
pRes = pEList->a[0].pExpr;
if( pRes->op!=TK_COLUMN ) return 0; /* Result is a column */
if( pRes->iTable!=pSrc->a[0].iCursor ) return 0; /* Not a correlated subq */
return 1;
}
#endif /* SQLITE_OMIT_SUBQUERY */