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>
Subject: Re: Adding REPACK [concurrently]
In-reply-to: <afoF8ypBbknkp8_b@alvherre.pgsql>
References: <afoF8ypBbknkp8_b@alvherre.pgsql>
Comments: In-reply-to Alvaro Herrera <alvherre@alvh.no-ip.org>
   message dated "Tue, 05 May 2026 17:02:39 +0200."
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=-=-="
Date: Wed, 06 May 2026 10:25:44 +0200
Message-ID: <77611.1778055944@localhost>
Archived-At: 
 <https://www.postgresql.org/message-id/77611.1778055944%40localhost>
Precedence: bulk

--=-=-=
Content-Type: text/plain

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


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=0001-Distinguish-properly-when-database-specific-transact.patch