On 11/21/2014 10:44 AM, Josh Berkus wrote: > Greg, > > >> This is actually the way it used to be. It was changed because it was >> discovered there was some case where an unfrozen xid would end up in >> template0 anyways and for some reason it was hard to be sure to avoid it. I >> don't recall exactly what the situation was that triggered it but the >> argument was made then that it was safest to just include template0 in >> autovacuum rather than depend on getting this 100% right and risk >> corruption. > > Right, and that was fine before pg_multixact, because even with 500m > XIDs in the bank, pg_clog is still pretty small. The problem is that > with the same number of multixacts, pg_multixact is around *16GB* in size. > > Thing is, template0 is just there as a check on users messing up > template1. Having that kind if precaution causing repeated operational > problems for users is not good design. Maybe we should just get rid of > template0 and come up with some other mechanism to reset template1 to > bare-bones state.
Or and even simpler solution: provide a way for the superuser to manually vacuum template0 *without* needing to update pg_database. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
