Re: A concurrent VACUUM FULL?

Erik Nordström <erik(at)timescale(dot)com> wrote:

> On Mon, Jun 30, 2025 at 1:46 PM Álvaro Herrera <alvherre(at)kurilemu(dot)de> wrote:
>
> On 2025-Jun-30, Erik Nordström wrote:
>
> > On Mon, Jun 30, 2025 at 12:03 PM Antonin Houska <ah(at)cybertec(dot)at> wrote:
>
> > > Patch [1] is in the queue that allows both reads and writes. (An exclusive
> > > lock is acquired here for the swaps, but that should be held for very short
> > > time.)
> >
> > That sounds great. Do you know if there's anything I can do to help?
>
> It would be very valuable if you can review the code, test it under the
> weirdest conditions you can imagine or just under normal conditions,
> proof-read the documentation, try to see if anything is missing that
> should be there, and so on. Everything that you would expect from a new
> feature released as part of the next Postgres release. Any
> problems/crashes/ abnormalities that you report before the patch is
> included in Postgres, is one less issue that we'll have to deal with
> after the release.
>
> I'll do my best to test the feature.

Thanks. I've noticed that the patch set needs rebase. I'll try to prepare a
new version today.

> One question I have, though, is why not start with supporting concurrent reads but not writes? That would
> already be a win and make the patch simpler.

It occurred to me at some point too, but I think it would be rather a
different implementation. So if we were to support both read-only and
read-write modes, the amount of code would be even higher.

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