From edbcbe277d795ecc339b0e4fa29bae42ce1a7be9 Mon Sep 17 00:00:00 2001 From: Etsuro Fujita Date: Thu, 9 May 2019 18:39:23 +0900 Subject: postgres_fdw: Fix cost estimation for aggregate pushdown. In commit 7012b132d0, which added support for aggregate pushdown in postgres_fdw, the expense of evaluating the final scan/join target computed by make_group_input_target() was not accounted for at all in costing aggregate pushdown paths with local statistics. The right fix for this would be to have a separate upper stage to adjust the final scan/join relation (see comments for apply_scanjoin_target_to_paths()); but for now, fix by adding the tlist eval cost when costing aggregate pushdown paths with local statistics. Apply this to HEAD only to avoid destabilizing existing plan choices. Author: Etsuro Fujita Reviewed-By: Antonin Houska Discussion: https://postgr.es/m/5C66A056.60007%40lab.ntt.co.jp --- src/backend/optimizer/plan/planner.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src/backend/optimizer/plan/planner.c') diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index eb6f5a354dc..48005434d40 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -7113,6 +7113,10 @@ apply_scanjoin_target_to_paths(PlannerInfo *root, * confused in createplan.c if they don't agree. We must do this now so * that any append paths made in the next part will use the correct * pathtarget (cf. create_append_path). + * + * Note that this is also necessary if GetForeignUpperPaths() gets called + * on the final scan/join relation or on any of its children, since the + * FDW might look at the rel's target to create ForeignPaths. */ rel->reltarget = llast_node(PathTarget, scanjoin_targets); -- cgit v1.2.3