left input's sorting, because null rows may be inserted at various points.
Per report from Ferenc Lutischá¸n.
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.67 2001/11/11 19:18:54 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.67.2.1 2005/01/23 02:25:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
cur_mergeclauses,
innerrel);
/* Build pathkeys representing output sort order. */
- merge_pathkeys = build_join_pathkeys(root, joinrel, outerkeys);
+ merge_pathkeys = build_join_pathkeys(root, joinrel, jointype,
+ outerkeys);
/*
* And now we can make the path. We only consider the cheapest-
* as a nestloop, and even if some of the mergeclauses are
* implemented by qpquals rather than as true mergeclauses):
*/
- merge_pathkeys = build_join_pathkeys(root, joinrel,
+ merge_pathkeys = build_join_pathkeys(root, joinrel, jointype,
outerpath->pathkeys);
if (nestjoinOK)
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.36 2001/11/11 20:33:53 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.36.2.1 2005/01/23 02:25:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* vars they were joined with; furthermore, it doesn't matter what kind
* of join algorithm is actually used.
*
+ * EXCEPTION: in a FULL or RIGHT join, we cannot treat the result as
+ * having the outer path's path keys, because null lefthand rows may be
+ * inserted at random points. It must be treated as unsorted.
+ *
* 'joinrel' is the join relation that paths are being formed for
+ * 'jointype' is the join type (inner, left, full, etc)
* 'outer_pathkeys' is the list of the current outer path's path keys
*
* Returns the list of new path keys.
List *
build_join_pathkeys(Query *root,
RelOptInfo *joinrel,
+ JoinType jointype,
List *outer_pathkeys)
{
+ if (jointype == JOIN_FULL || jointype == JOIN_RIGHT)
+ return NIL;
+
/*
* This used to be quite a complex bit of code, but now that all
* pathkey sublists start out life canonicalized, we don't have to do
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: paths.h,v 1.59 2001/11/05 17:46:34 momjian Exp $
+ * $Id: paths.h,v 1.59.2.1 2005/01/23 02:26:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
ScanDirection scandir);
extern List *build_join_pathkeys(Query *root,
RelOptInfo *joinrel,
+ JoinType jointype,
List *outer_pathkeys);
extern List *make_pathkeys_for_sortclauses(List *sortclauses,
List *tlist);
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