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| author | Etsuro Fujita <efujita@postgresql.org> | 2019-05-09 18:39:23 +0900 |
|---|---|---|
| committer | Etsuro Fujita <efujita@postgresql.org> | 2019-05-09 18:39:23 +0900 |
| commit | edbcbe277d795ecc339b0e4fa29bae42ce1a7be9 (patch) | |
| tree | 54f2a822cf33f9dbe451c771a8799b9ba1477097 /src/backend/optimizer/plan/planner.c | |
| parent | 47a338cfcd67139a1f91892b080934fcfc3aea03 (diff) | |
| download | postgresql-edbcbe277d795ecc339b0e4fa29bae42ce1a7be9.tar.gz postgresql-edbcbe277d795ecc339b0e4fa29bae42ce1a7be9.zip | |
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
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 4 |
1 files changed, 4 insertions, 0 deletions
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); |