database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-06 07:49:08 +03:00
Code Activity

Fix some issues with LATERAL(SELECT UNION ALL SELECT).

Browse Source 
The LATERAL marking has to be propagated down to the UNION leaf queries
when we pull them up.  Also, fix the formerly stubbed-off
set_append_rel_pathlist().  It does already have enough smarts to cope with
making a parameterized Append path at need; it just has to not assume that
there *must* be an unparameterized path.
This commit is contained in:
Tom Lane
2012-08-11 18:42:20 -04:00
parent 83af58f6b5
commit e76af54137
4 changed files with 94 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
src/backend/optimizer/prep/prepjointree.c
View File

@@ -995,20 +995,45 @@ pull_up_simple_union_all(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte)
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
Query *subquery = rte->subquery;
int rtoffset;
int rtoffset = list_length(root->parse->rtable);
List *rtable;
/*
* Append child RTEs to parent rtable.
*
* Make a modifiable copy of the subquery's rtable, so we can adjust
* upper-level Vars in it. There are no such Vars in the setOperations
* tree proper, so fixing the rtable should be sufficient.
*/
rtable = copyObject(subquery->rtable);
/*
* Upper-level vars in subquery are now one level closer to their parent
* than before. We don't have to worry about offsetting varnos, though,
* because any such vars must refer to stuff above the level of the query
* we are pulling into.
* because the UNION leaf queries can't cross-reference each other.
*/
rtoffset = list_length(root->parse->rtable);
rtable = copyObject(subquery->rtable);
IncrementVarSublevelsUp_rtable(rtable, -1, 1);
/*
* If the UNION ALL subquery had a LATERAL marker, propagate that to all
* its children. The individual children might or might not contain any
* actual lateral cross-references, but we have to mark the pulled-up
* child RTEs so that later planner stages will check for such.
*/
if (rte->lateral)
{
ListCell *rt;
foreach(rt, rtable)
{
RangeTblEntry *child_rte = (RangeTblEntry *) lfirst(rt);
Assert(child_rte->rtekind == RTE_SUBQUERY);
child_rte->lateral = true;
}
}
/*
* Append child RTEs to parent rtable.
*/
root->parse->rtable = list_concat(root->parse->rtable, rtable);
/*