Hi, I think this bugfix needs to be backpatched to v12 too.
See backtrace / repro SQL here - https://www.postgresql.org/message-id/17713-92cce66de7e81c04%40postgresql.org - Robins Tharakan Amazon Web Services On Fri, 5 Feb 2021 at 17:05, Etsuro Fujita <efuj...@postgresql.org> wrote: > > postgres_fdw: Fix assertion in estimate_path_cost_size(). > > Commit 08d2d58a2 added an assertion assuming that the retrieved_rows > estimate for a foreign relation, which is re-used to cost pre-sorted > foreign paths with local stats, is set to at least one row in > estimate_path_cost_size(), which isn't correct because if the relation > is a foreign table with tuples=0, the estimate would be set to 0 there > when not using remote estimates. > > Per bug #16807 from Alexander Lakhin. Back-patch to v13 where the > aforementioned commit went in. > > Author: Etsuro Fujita > Reviewed-by: Kyotaro Horiguchi > Discussion: https://postgr.es/m/16807-9fe4e08fbaa5c7ce%40postgresql.org > > Branch > ------ > REL_13_STABLE > > Details > ------- > https://git.postgresql.org/pg/commitdiff/984384129bb8a92481d4f7ddd5dede2d781b191f > > Modified Files > -------------- > contrib/postgres_fdw/expected/postgres_fdw.out | 18 ++++++++++++++++++ > contrib/postgres_fdw/postgres_fdw.c | 2 +- > contrib/postgres_fdw/sql/postgres_fdw.sql | 12 ++++++++++++ > 3 files changed, 31 insertions(+), 1 deletion(-) >