Sorry, I meant to cc this to -bugs as well as -hackers
---------- Forwarded message ---------- From: Dean Rasheed <dean.a.rash...@gmail.com> Date: 18 August 2010 18:29 Subject: Per-tuple memory leak in 9.0 To: pgsql-hack...@postgresql.org While testing triggers, I came across the following memory leak. Here's a simple test case: CREATE TABLE foo(a int); CREATE OR REPLACE FUNCTION trig_fn() RETURNS trigger AS $$ BEGIN RETURN NEW; END; $$ LANGUAGE plpgsql; CREATE TRIGGER ins_trig BEFORE INSERT ON foo FOR EACH ROW EXECUTE PROCEDURE trig_fn(); INSERT INTO foo SELECT g FROM generate_series(1, 5000000) AS g; Memory usage goes up by around 100 bytes per row for the duration of the query. The problem is that the trigger code assumes that anything it allocates in the per-tuple memory context will be freed per-tuple processed, which used to be the case because the loop in ExecutePlan() calls ResetPerTupleExprContext() once each time round the loop, and that used to correspond to once per tuple. However, with the refactoring of that code out to nodeModifyTable.c, this is no longer the case because the ModifyTable node processes all the tuples from the subquery before returning, so I guess that the loop in ExecModifyTable() needs to call ResetPerTupleExprContext() each time round. Regards, Dean -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
