Re: [CORE] back-branch multixact fixes & 9.5 alpha/beta: schedule

On Mon, Jun 8, 2015 at 01:53:42PM -0300, Alvaro Herrera wrote:
> * people with the wrong oldestMulti setting in pg_control (which would
> be due to a buggy pg_upgrade being used long ago) will be unable to
> start if they upgrade to 9.3.7 or 9.3.8. A solution for them would be
> to downgrade to 9.3.6. We had reports of this problem starting just a
> couple of days after we released 9.4.2, I think.
>
> * We had a customer unable to refresh their base backups once they
> upgraded to 9.3.7; taking a new base backup would fail with a very
> similar error to those above (except no buggy pg_upgrade was involved).
> They seem to have gotten from under that problem by removing from
> crontab a script that ran whole-table vacuuming more frequently than
> with default settings. Their data is 3 TB in size, so the basebackup
> takes long enough that multixact truncations occured while the base
> backups were running, every time, so they were unrestorable.
>
> (Actually I just checked and it seems they haven't verified that they
> can take a new base backup -- the new one is still running.)
>
> Anyway my point is that for some guys these bugs are pretty critical.

OK, thanks for the summary. I assume they would still have problems
with 9.4.3.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ Everyone has their own god. +