> > One more question I have though is: > > How do you make sure noone (e.g. autovacuum analyze) > > unfreezes tuples after the vacuum freeze ? > > I will start a new thread to answer this question, but the short answer > is that the freeze only needs to happen in a fresh initdb database, and > once clog is copied over, new transactions can be created normally.
Yes. I am still answering here because my question was related to upgrade. I think you need to turn off autovacuum before freezing to avoid a later analyze that unfreezes pg_class (or the stats table). Also to really have all tables frozen I think the order of the freezes is crutial. Consider the order: freeze pg_class freeze pg_columns --> won't this unfreeze pg_class ? And what about shared catalogs ? Or does heap_update not change the xid ? Or can it use a frozen xid ? Or does it all work when done in one large transaction ? I think I am confused, sorry :-( Andreas -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
