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Do not apply the query flattening optimization when the outer query is an

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aggregate and the inner query contains an ORDER BY clause.  Ticket #2943. (CVS 4791)

FossilOrigin-Name: 6d33cbd99cb0db680767ceb31ec6345e90a805bc
This commit is contained in:
drh
2008-02-15 14:33:03 +00:00
parent 52391cb406
commit c52e355de1
4 changed files with 76 additions and 18 deletions
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17
src/select.c
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@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.413 2008/02/13 18:25:27 danielk1977 Exp $
** $Id: select.c,v 1.414 2008/02/15 14:33:04 drh Exp $
*/
#include "sqliteInt.h"
@@ -2417,6 +2417,10 @@ static void substSelect(
** subquery does not have both an ORDER BY and a LIMIT clause.
** (See ticket #2339)
**
** (16) The outer query is not an aggregate or the subquery does
** not contain ORDER BY. (Ticket #2942) This used to not matter
** until we introduced the group_concat() function.
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
@@ -2474,6 +2478,7 @@ static int flattenSubquery(
if( (p->disallowOrderBy || p->pOrderBy) && pSub->pOrderBy ){
return 0; /* Restriction (11) */
}
if( isAgg && pSub->pOrderBy ) return 0; /* Restriction (16) */
/* Restriction 3: If the subquery is a join, make sure the subquery is
** not used as the right operand of an outer join. Examples of why this
@@ -3143,16 +3148,6 @@ int sqlite3Select(
}
#endif
/* Check for the special case of a min() or max() function by itself
** in the result set.
*/
#if 0
if( simpleMinMaxQuery(pParse, p, pDest) ){
rc = 0;
goto select_end;
}
#endif
/* Check to see if this is a subquery that can be "flattened" into its parent.
** If flattening is a possiblity, do so and return immediately.
*/