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In a nestloop inner indexscan, it's OK to use pushed-down baserestrictinfo

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clauses even if it's an outer join.  This is a corner case since such
clauses could only arise from weird OUTER JOIN ON conditions, but worth
fixing.  Per example from Ron at cheapcomplexdevices.com.
This commit is contained in:
Tom Lane 2005-12-06 16:50:36 +00:00
parent 974c5a8730
commit 953208a34c
1 changed files with 12 additions and 22 deletions
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34
src/backend/optimizer/path/indxpath.c
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@ -9,7 +9,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.195 2005/11/30 17:10:19 tgl Exp $ * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.196 2005/12/06 16:50:36 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -1357,27 +1357,9 @@ find_clauses_for_join(PlannerInfo *root, RelOptInfo *rel,
Relids outer_relids, bool isouterjoin) Relids outer_relids, bool isouterjoin)
{ {
List *clause_list = NIL; List *clause_list = NIL;
bool jfound = false;
Relids join_relids; Relids join_relids;
ListCell *l; ListCell *l;
/*
* We can always use plain restriction clauses for the rel. We scan these
* first because we want them first in the clause list for the convenience
* of remove_redundant_join_clauses, which can never remove non-join
* clauses and hence won't be able to get rid of a non-join clause if it
* appears after a join clause it is redundant with.
*/
foreach(l, rel->baserestrictinfo)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
/* Can't use pushed-down clauses in outer join */
if (isouterjoin && rinfo->is_pushed_down)
continue;
clause_list = lappend(clause_list, rinfo);
}
/* Look for joinclauses that are usable with given outer_relids */ /* Look for joinclauses that are usable with given outer_relids */
join_relids = bms_union(rel->relids, outer_relids); join_relids = bms_union(rel->relids, outer_relids);
@ -1385,22 +1367,30 @@ find_clauses_for_join(PlannerInfo *root, RelOptInfo *rel,
{ {
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l); RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
/* Can't use pushed-down clauses in outer join */ /* Can't use pushed-down join clauses in outer join */
if (isouterjoin && rinfo->is_pushed_down) if (isouterjoin && rinfo->is_pushed_down)
continue; continue;
if (!bms_is_subset(rinfo->required_relids, join_relids)) if (!bms_is_subset(rinfo->required_relids, join_relids))
continue; continue;
clause_list = lappend(clause_list, rinfo); clause_list = lappend(clause_list, rinfo);
jfound = true;
} }
bms_free(join_relids); bms_free(join_relids);
/* if no join clause was matched then forget it, per comments above */ /* if no join clause was matched then forget it, per comments above */
if (!jfound) if (clause_list == NIL)
return NIL; return NIL;
/*
* We can also use any plain restriction clauses for the rel. We put
* these at the front of the clause list for the convenience of
* remove_redundant_join_clauses, which can never remove non-join clauses
* and hence won't be able to get rid of a non-join clause if it appears
* after a join clause it is redundant with.
*/
clause_list = list_concat(list_copy(rel->baserestrictinfo), clause_list);
/* /*
* We may now have clauses that are known redundant. Get rid of 'em. * We may now have clauses that are known redundant. Get rid of 'em.
*/ */