Re: [GENERAL] startup process stuck in recovery

> On Oct 10, 2017, at 08:05, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> You're right, I was testing on HEAD, so that patch might've obscured
> the problem.  But the code looks like it could still be O(N^2) in
> some cases.  Will look again later.

I was able to reproduce this on 9.5.9 with the following:

DO $$
DECLARE  i int := 1;
BEGIN  FOR i IN 1..12000 LOOP     BEGIN         PERFORM f();         i := i / 0;     EXCEPTION        WHEN
division_by_zeroTHEN     END;  END LOOP; 
END;
$$ language plpgsql;

where f() is:

CREATE OR REPLACE FUNCTION f() RETURNS VOID AS $$
BEGIN CREATE TEMPORARY TABLE test_table ON COMMIT DROP AS SELECT i FROM generate_series(1, 100) i;
END:
$$ language plpgsql;

A couple of observations:

-- In this version, I couldn't do a select * from pg_locks() on the secondary without getting an out-of-shared-memory
error.
-- If I increased max_locks_per_transaction to 15000, the problem didn't occur, even if I bumped up the number of
iterationsin the first to 20000. 

--
-- Christophe Pettus  xof@thebuild.com



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