Re: Wrong return code in vacuumdb when multiple jobs are used

On Sat, May 04, 2019 at 10:35:23AM +0200, Julien Rouhaud wrote:
> While reading vacuumdb code, I just noticed that it can return 0 if an
> error happen when -j is used, if errors happen on the last batch of
> commands.

Yes, I agree that this is wrong. GetIdleSlot() is much more careful
about that than vacuum_one_database(), so your patch looks good at
quick glance.

> This behavior exists since 9.5. Trivial patch attached. I'm not sure
> that a TAP test is required here, so I didn't add one. I'll be happy
> to do so though if needed.

You could make that reliable by getting a lock on a table using a
two-phase transaction, and your test case from upthread won't fly high
as we have no facility in PostgresNode.pm to keep around a session's
state using psql. FWIW, I am not convinced that it is a case worth
bothering, so no tests is fine.
--
Michael