Fix an oversight in convert_EXISTS_sublink_to_join: we can't convert an

EXISTS that contains a WITH clause.  This would usually lead to a
"could not find CTE" error later in planning, because the WITH wouldn't
get processed at all.  Noted while playing with an example from Ken Marshall.
This commit is contained in:
Tom Lane 2010-01-18 18:17:45 +00:00
parent a0a7e63434
commit a49147af78

View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.157 2010/01/02 16:57:47 momjian Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.158 2010/01/18 18:17:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1114,6 +1114,17 @@ convert_EXISTS_sublink_to_join(PlannerInfo *root, SubLink *sublink,
Assert(sublink->subLinkType == EXISTS_SUBLINK);
/*
* Can't flatten if it contains WITH. (We could arrange to pull up the
* WITH into the parent query's cteList, but that risks changing the
* semantics, since a WITH ought to be executed once per associated query
* call.) Note that convert_ANY_sublink_to_join doesn't have to reject
* this case, since it just produces a subquery RTE that doesn't have to
* get flattened into the parent query.
*/
if (subselect->cteList)
return NULL;
/*
* Copy the subquery so we can modify it safely (see comments in
* make_subplan).