duncan.bu...@orionvm.com.au writes: > I found that running a SELECT FOR UPDATE query in a CTE does not block > simultaneous transactions from running the same query.
The reason this test case doesn't do anything: > CREATE FUNCTION lock_0(int) returns int as $$ > WITH locked as ( > SELECT 1 FROM foo > WHERE x = $1 > FOR UPDATE) > SELECT 1 > $$ LANGUAGE SQL; is that the CTE is unreferenced. While we force INSERT/UPDATE/DELETE CTEs to be executed even when not referenced, that does not apply to SELECTs; see http://www.postgresql.org/docs/9.1/static/queries-with.html which states "execution of a SELECT is carried only as far as the primary query demands its output". If I change the function to say "WITH ... SELECT * FROM locked" then blocking occurs as expected. regards, tom lane -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
