Re: [COMMITTERS] pgsql: Add amcheck extension to contrib.

Andres Freund <andres(at)anarazel(dot)de> writes:
> Add amcheck extension to contrib.

axolotl just failed on this:
https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=axolotl&dt=2017-03-13%2017%3A49%3A24

***************
*** 78,86 ****

-- make sure we don't have any leftover locks
SELECT * FROM pg_locks WHERE relation IN ('bttest_a_idx'::regclass, 'bttest_b_idx'::regclass);
! locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted | fastpath
! ----------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-----+------+---------+----------
! (0 rows)

COMMIT;
-- cleanup
--- 78,87 ----

-- make sure we don't have any leftover locks
SELECT * FROM pg_locks WHERE relation IN ('bttest_a_idx'::regclass, 'bttest_b_idx'::regclass);
! locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted | fastpath
! ----------+----------+----------+------+-------+------------+---------------+---------+-------+----------+--------------------+-------+-----------------+---------+----------
! relation | 57562 | 57573 | | | | | | | | 4/29 | 20342 | AccessShareLock | t | t
! (1 row)

COMMIT;
-- cleanup

I could be wrong, but the most obvious explanation for this failure is
that autovacuum had a lock on the table or index when we looked.
Even if that isn't why axolotl failed in this particular case, I think
it's dead certain that we will see such failures from time to time
if this test script isn't tightened up. IIUC what the test is trying
to look for, I think adding "AND pid = pg_backend_pid()" to this query
would be an appropriate fix.

regards, tom lane