RE: visibility map corruption

> On Sun, Jul 4, 2021 at 1:44 PM Floris Van Nee <florisvannee@optiver.com>
> wrote:
> > We recently ran into an issue where the visibility map of a relation was
> corrupt, running Postgres 12.4. The error we'd get when running a SELECT *
> from this table is:
> >
> > could not access status of transaction 3704450152
> > DETAIL:  Could not open file "pg_xact/0DCC": No such file or directory.
> 
> Have you ever used pg_upgrade on this database?
> 

Yes. The last time (from v11 to v12) was in October 2020. The transaction id in the tuples (the one PG is trying to
checkin the tx log) dated from February 2021. I do believe (but am not 100% certain) that the affected table already
existedat the time of the last pg_upgrade though.