Re: BUG #17257: (auto)vacuum hangs within lazy_scan_prune()

On Tue, Jan 09, 2024 at 03:59:19PM -0500, Peter Geoghegan wrote:
> On Sat, Jan 6, 2024 at 3:24 PM Noah Misch <noah(at)leadboat(dot)com> wrote:
> > On Sun, Dec 31, 2023 at 03:53:34PM -0800, Peter Geoghegan wrote:
> > > I am aware of a production database that appears to run into the same
> > > problem. Inserts and concurrent cross-partition updates are used
> > > heavily on this instance (the table in question uses partitioning).
> > > Perhaps you happened upon a similar problematic production database,
> > > and found this thread when researching the issue? Maybe we've both
> > > seen the same problem in the wild?
> >
> > I did find this thread while researching the symptoms I was seeing. No
> > partitioning where I saw them.
>
> I'm starting to think that partitioning was just a red herring. The
> instance had problems in the presence of DELETEs, not UPDATEs (or
> cross-partition UPDATEs).
>
> Did the affected system that you investigated happen to have an
> atypically high number of databases? The system 15.4 system that I saw
> the problem on had almost 3,000 databases.

No, single-digit database count here.