diff options
| -rw-r--r-- | src/backend/optimizer/plan/subselect.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index 887f360c0ee..2e99cc6b4ba 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -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 $ * *------------------------------------------------------------------------- */ @@ -1115,6 +1115,17 @@ 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). */ |