On Fri, Jul 5, 2019 at 3:17 PM Robert Haas <robertmhaas@gmail.com> wrote:
> I don't know whether or not this is a bug, but my guess is that it
> isn't. pg_database and several other system catalogs are shared
> relations, which means that they are shared by all databases. So, it's
> not too surprising that you could get some interaction between VACUUM
> FULL command in different databases. Routine use of VACUUM FULL is
> something that should be avoided, so it doesn't seem like a huge
> problem to me that you can't run 32 of them at the same time.
>
To clarify (since it came up a couple of times in this thread): The
deadlocks can also be observed with significantly less threads and
(many) statements in between. My initial bug report used 32 threads
and only VACUUM to make it easy to quickly reproduce the deadlocks.