| From: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
|---|---|
| To: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
| Cc: | Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: freezing multixacts |
| Date: | 2012-02-06 15:57:30 |
| Message-ID: | CA+U5nMJudDzPQZ=9tRKvvVZYuWm8UnxO_VNF9=tJYRp=8LeoXA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Thu, Feb 2, 2012 at 4:33 AM, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> However, there are cases where not even that is possible -- consider
> tuple freezing during WAL recovery. Recovery is going to need to
> replace those multis with other multis, but it cannot create new multis
> itself. The only solution here appears to be that when multis are
> frozen in the master, replacement multis have to be logged too. So the
> heap_freeze_tuple Xlog record will have a map of old multi to new. That
> way, recovery can just determine the new multi to use for any particular
> old multi; since multixact creation is also logged, we're certain that
> the replacement value has already been defined.
Multixacts are ignored during recovery. Why do anything at all?
--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Robert Haas | 2012-02-06 16:19:14 | Re: freezing multixacts |
| Previous Message | Gabriele Bartolini | 2012-02-06 15:10:15 | Re: Dry-run mode for pg_archivecleanup |