diff options
Diffstat (limited to 'src/backend/optimizer/plan/createplan.c')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index b068d2f3f83..41238b7c0e6 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 1.266 2009/10/26 02:26:33 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.267 2009/11/15 02:45:35 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1664,9 +1664,8 @@ create_mergejoin_plan(PlannerInfo *root, best_path->jpath.outerjoinpath->parent->relids); /* - * Create explicit sort nodes for the outer and inner join paths if - * necessary. The sort cost was already accounted for in the path. Make - * sure there are no excess columns in the inputs if sorting. + * Create explicit sort nodes for the outer and inner paths if necessary. + * Make sure there are no excess columns in the inputs if sorting. */ if (best_path->outersortkeys) { @@ -1695,23 +1694,17 @@ create_mergejoin_plan(PlannerInfo *root, innerpathkeys = best_path->jpath.innerjoinpath->pathkeys; /* - * If inner plan is a sort that is expected to spill to disk, add a - * materialize node to shield it from the need to handle mark/restore. - * This will allow it to perform the last merge pass on-the-fly, while in - * most cases not requiring the materialize to spill to disk. - * - * XXX really, Sort oughta do this for itself, probably, to avoid the - * overhead of a separate plan node. + * If specified, add a materialize node to shield the inner plan from + * the need to handle mark/restore. */ - if (IsA(inner_plan, Sort) && - sort_exceeds_work_mem((Sort *) inner_plan)) + if (best_path->materialize_inner) { Plan *matplan = (Plan *) make_material(inner_plan); /* * We assume the materialize will not spill to disk, and therefore * charge just cpu_tuple_cost per tuple. (Keep this estimate in sync - * with similar ones in cost_mergejoin and create_mergejoin_path.) + * with cost_mergejoin.) */ copy_plan_costsize(matplan, inner_plan); matplan->total_cost += cpu_tuple_cost * matplan->plan_rows; @@ -1887,6 +1880,7 @@ create_mergejoin_plan(PlannerInfo *root, inner_plan, best_path->jpath.jointype); + /* Costs of sort and material steps are included in path cost already */ copy_path_costsize(&join_plan->join.plan, &best_path->jpath.path); return join_plan; |