From 2466d6654f85d7ec136d09d52ae22771452a19df Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 28 Mar 2024 11:31:03 +0100 Subject: libpq-be-fe-helpers.h: wrap new cancel APIs Commit 61461a300c1c introduced new functions to libpq for cancelling queries. This commit introduces a helper function that backend-side libraries and extensions can use to invoke those. This function takes a timeout and can itself be interrupted while it is waiting for a cancel request to be sent and processed, instead of being blocked. This replaces the usage of the old functions in postgres_fdw and dblink. Finally, it also adds some test coverage for the cancel support in postgres_fdw. Author: Jelte Fennema-Nio Discussion: https://postgr.es/m/CAGECzQT_VgOWWENUqvUV9xQmbaCyXjtRRAYO8W07oqashk_N+g@mail.gmail.com --- contrib/postgres_fdw/expected/postgres_fdw.out | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'contrib/postgres_fdw/expected') diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out index 3f0110c52b9..b7af86d3511 100644 --- a/contrib/postgres_fdw/expected/postgres_fdw.out +++ b/contrib/postgres_fdw/expected/postgres_fdw.out @@ -2739,6 +2739,21 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c (10 rows) ALTER VIEW v4 OWNER TO regress_view_owner; +-- Make sure this big CROSS JOIN query is pushed down +EXPLAIN (VERBOSE, COSTS OFF) SELECT count(*) FROM ft1 CROSS JOIN ft2 CROSS JOIN ft4 CROSS JOIN ft5; + QUERY PLAN +--------------------------------------------------------------------------------------------------------------------------------------------------------------------- + Foreign Scan + Output: (count(*)) + Relations: Aggregate on ((((public.ft1) INNER JOIN (public.ft2)) INNER JOIN (public.ft4)) INNER JOIN (public.ft5)) + Remote SQL: SELECT count(*) FROM ((("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (TRUE)) INNER JOIN "S 1"."T 3" r4 ON (TRUE)) INNER JOIN "S 1"."T 4" r6 ON (TRUE)) +(4 rows) + +-- Make sure query cancellation works +SET statement_timeout = '10ms'; +select count(*) from ft1 CROSS JOIN ft2 CROSS JOIN ft4 CROSS JOIN ft5; -- this takes very long +ERROR: canceling statement due to statement timeout +RESET statement_timeout; -- ==================================================================== -- Check that userid to use when querying the remote table is correctly -- propagated into foreign rels present in subqueries under an UNION ALL -- cgit v1.2.3