From 69f75bf825f83dc506e73cf88f0adde541c39004 Mon Sep 17 00:00:00 2001 From: Etsuro Fujita Date: Thu, 15 Dec 2022 21:15:00 +0900 Subject: postgres_fdw: Fix assertion in estimate_path_cost_size(). Commit 08d2d58a2 added this assertion assuming that the retrieved_rows estimate for a foreign relation is set to at least one row in estimate_path_cost_size(), but the assumption isn't correct because if the relation is a foreign table with tuples=0, the estimate would be set to 0 in there when using local stats, and if the query's WHERE clause has a NULL condition, the estimate could be set to 0 in there when using remote estimates. (Note: even in the latter case the assertion could be reachable when costing foreign final paths.) Repair. Per bug #17713 from Robins Tharakan. This patch was already applied to v13 or later; apply it to v12 as well where the aforementioned commit was added. Thanks to Richard Guo for investigation. Discussion: http://postgr.es/m/17713-92cce66de7e81c04%40postgresql.org Discussion: http://postgr.es/m/CAEP4nAza%2B0fTCLkgkKYux3JDo3tUBTQORehP%2BaCxSNURpSFpHw%40mail.gmail.com --- contrib/postgres_fdw/postgres_fdw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index a4d0377f31f..7aa6d7c549c 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -2749,7 +2749,7 @@ estimate_path_cost_size(PlannerInfo *root, */ if (fpinfo->rel_startup_cost >= 0 && fpinfo->rel_total_cost >= 0) { - Assert(fpinfo->retrieved_rows >= 1); + Assert(fpinfo->retrieved_rows >= 0); rows = fpinfo->rows; retrieved_rows = fpinfo->retrieved_rows; -- cgit v1.2.3