Thread: pgsql: postgres_fdw: Fix cost estimation for aggregate pushdown.
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 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/edbcbe277d795ecc339b0e4fa29bae42ce1a7be9 Modified Files -------------- contrib/postgres_fdw/postgres_fdw.c | 16 +++++++++++++--- src/backend/optimizer/plan/planner.c | 4 ++++ 2 files changed, 17 insertions(+), 3 deletions(-)