Adjust the definition of is_pushed_down so that it's always true for INNER

JOIN quals, just like WHERE quals, even if they reference every one of the
join's relations.  Now that we can reorder outer and inner joins, it's
possible for such a qual to end up being assigned to an outer join plan node,
and we mustn't have it treated as a join qual rather than a filter qual for
the node.  (If it were, the join could produce null-extended rows that it
shouldn't.)  Per bug report from Pelle Johansson.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index c67c067a5f2..dac7d959bbd 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.134 2007/01/22 20:00:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.135 2007/02/16 20:57:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -797,14 +797,14 @@ typedef struct HashPath
  * join, we prevent it from being evaluated below the outer join's joinrel.
  * When we do form the outer join's joinrel, we still need to distinguish
  * those quals that are actually in that join's JOIN/ON condition from those
- * that appeared higher in the tree and were pushed down to the join rel
+ * that appeared elsewhere in the tree and were pushed down to the join rel
  * because they used no other rels.  That's what the is_pushed_down flag is
- * for; it tells us that a qual came from a point above the join of the
- * set of base rels listed in required_relids.	A clause that originally came
- * from WHERE will *always* have its is_pushed_down flag set; a clause that
- * came from an INNER JOIN condition, but doesn't use all the rels being
- * joined, will also have is_pushed_down set because it will get attached to
- * some lower joinrel.
+ * for; it tells us that a qual is not an OUTER JOIN qual for the set of base
+ * rels listed in required_relids.  A clause that originally came from WHERE
+ * or an INNER JOIN condition will *always* have its is_pushed_down flag set.
+ * It's possible for an OUTER JOIN clause to be marked is_pushed_down too,
+ * if we decide that it can be pushed down into the nullable side of the join.
+ * In that case it acts as a plain filter qual for wherever it gets evaluated.
  *
  * When application of a qual must be delayed by outer join, we also mark it
  * with outerjoin_delayed = true.  This isn't redundant with required_relids