Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin

On Tue, Jul 2, 2024 at 7:07 PM Melanie Plageman
<melanieplageman(at)gmail(dot)com> wrote:
>
> On Mon, Jun 24, 2024 at 4:27 AM Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
> >
> > Would it be possible to make it robust so that we could always run it
> > with "make check"? This seems like an important corner case to
> > regression test.
>
> Okay, I've attached a new version of the patch and a new version of
> the repro that may be fast and stable enough to commit. It is more
> minimal than the previous version. I made the table as small as I
> could to still trigger two rounds of index vacuuming. I tried to make
> it as stable as possible. I also removed the cursor on the standby
> that could trigger recovery conflicts. It would be super helpful if
> someone could take a look at the test and point out any ways I could
> make it even more likely to be stable.

Attached v3 has one important additional component in the test -- I
use pg_stat_progress_vacuum to confirm that we actually do more than
one pass of index vacuuming. Otherwise, it would have been trivial for
the test to incorrectly pass.

I could still use another pair of eyes on the test (looking out for
stability enhancing measures I could take). I also would be happy if
someone looked at the commit message and/or comments to let me know if
they make sense.

I'll finish with versions of the patch and test targeted at v14-16 and
propose those before committing this.

- Melanie