From cc5e80b8d1c4bf86aa99b54c938e9048e10bf93a Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 2 Jul 2005 23:00:42 +0000 Subject: Teach planner about some cases where a restriction clause can be propagated inside an outer join. In particular, given LEFT JOIN ON (A = B) WHERE A = constant, we cannot conclude that B = constant at the top level (B might be null instead), but we can nonetheless put a restriction B = constant into the quals for B's relation, since no inner-side rows not meeting that condition can contribute to the final result. Similarly, given FULL JOIN USING (J) WHERE J = constant, we can't directly conclude that either input J variable = constant, but it's OK to push such quals into each input rel. Per recent gripe from Kim Bisgaard. Along the way, remove 'valid_everywhere' flag from RestrictInfo, as on closer analysis it was not being used for anything, and was defined backwards anyway. --- src/backend/optimizer/plan/createplan.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'src/backend/optimizer/plan/createplan.c') diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 76812e2e4b3..959c17206c0 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.192 2005/06/10 22:25:36 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.193 2005/07/02 23:00:41 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1176,8 +1176,7 @@ create_nestloop_plan(PlannerInfo *root, List *bitmapclauses; bitmapclauses = - make_restrictinfo_from_bitmapqual(innerpath->bitmapqual, - true, true); + make_restrictinfo_from_bitmapqual(innerpath->bitmapqual, true); joinrestrictclauses = select_nonredundant_join_clauses(root, joinrestrictclauses, -- cgit v1.2.3