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 <postgres@jeltef.nl>
Discussion: https://postgr.es/m/CAGECzQT_VgOWWENUqvUV9xQmbaCyXjtRRAYO8W07oqashk_N+g@mail.gmail.com
---
 contrib/postgres_fdw/sql/postgres_fdw.sql | 7 +++++++
 1 file changed, 7 insertions(+)

(limited to 'contrib/postgres_fdw/sql/postgres_fdw.sql')

diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 5fffc4c53bd..6e1c819159c 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -737,6 +737,13 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c
 SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
 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;
+-- 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
+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

