Don't pass grouped relations to FDWs
build_grouped_rel() makes a flat copy of the input relation, including
its FDW fields. As a result, when building a grouped join relation
for eager aggregation, add_paths_to_joinrel() called the FDW's
GetForeignJoinPaths for it. postgres_fdw then failed with "Aggref
found where not expected" on the partial Aggrefs in the target list,
and in any case it would have treated a partially aggregated input as
a plain foreign scan.
FDWs are not prepared to handle grouped relations, so clear serverid,
fdwroutine and fdw_private in build_grouped_rel().
Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CA+Tgmob7iSM9YkRM44VjUDuaCchW-fY54MV5njpTZTL9uNyV4w@mail.gmail.com
Backpatch-through: 19
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/58fca6bdf26f55484c11bf505ae699ec240d60cb
Modified Files
--------------
contrib/postgres_fdw/expected/postgres_fdw.out | 26 ++++++++++++++++++++++++++
contrib/postgres_fdw/sql/postgres_fdw.sql | 5 +++++
src/backend/optimizer/util/relnode.c | 7 +++++++
3 files changed, 38 insertions(+)
