Re: Adding REPACK [concurrently]

Antonin Houska <ah@cybertec.at>

From: Antonin Houska <ah@cybertec.at>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Mihail Nikalayeu <mihailnikalayeu@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Srinath Reddy Sadipiralla <srinath2133@gmail.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Pg Hackers <pgsql-hackers@lists.postgresql.org>, Robert Treat <rob@xzilla.net>
Date: 2026-05-06T08:25:44Z
Lists: pgsql-hackers

Attachments

Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

> On 2026-May-05, Antonin Houska wrote:
> 
> > However, I failed to notice that COMMIT record of
> > a transaction listed in the xl_running_xacts WAL record is not guaranteed to
> > follow the xl_running_xacts record in WAL. In other words, even if
> > xl_running_xacts is created before a COMMIT record of the contained
> > transaction, it may end up at higher LSN in WAL. So the cleanup I relied on
> > might not take place.
> 
> That's pretty bad news.
> 
> > I've got no good idea how to fix that.

One idea occurred to me yet, effectively it's just a cleanup. Part of it was
already proposed [1].

[1] https://www.postgresql.org/message-id/flat/CAHg%2BQDcQak4jx_6X2_Ws98rzG%3DxBARLjqm_%3D56wTRUtNsY4DZQ%40mail.gmail.com

-- 
Antonin Houska
Web: https://www.cybertec-postgresql.com