Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin
Date
Msg-id CA+TgmoYWmSwUVG+TZ6jfjX3UqjTGJzbcFyW0Qjm-2hGKdMEwcA@mail.gmail.com
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In response to Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Tue, Jun 25, 2024 at 4:41 PM Andres Freund <andres@anarazel.de> wrote:
> I doubt that's doable in the back branches. And even on HEAD, I don't think
> it's a particularly attractive option - there's just a global vistest for each
> of the types of objects with a specific horizon (they need to be updated
> occasionally, e.g. when taking snapshots). So there's not really a spot to put
> an associated OldestXmin. We could put it there and remove it at the end of
> vacuum / in an exception handler, but that seems substantially worse.

Oh, right: I forgot that the visibility test objects were just
pointers to global variables.

Well, I don't know. I guess that doesn't leave any real options but to
fix it as Melanie proposed. But I still don't like it very much. I
feel like having to test against two different thresholds in the
pruning code is surely a sign that we're doing something wrong.

--
Robert Haas
EDB: http://www.enterprisedb.com



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