Jeff Davis wrote: > On Thu, 2011-04-07 at 22:21 -0400, Bruce Momjian wrote: > > One concern I have is that existing heap tables are protecting clog > > files, but once those are frozen, the system might remove clog files not > > realizing it has to freeze the heap tables too. > > I don't understand. Can you elaborate?
Well, when you initially run pg_upgrade, your heap relfrozenxid is preserved, and we only remove clog files when _all_ relations in all database do not need them, so for a time the heap tables will keep the clogs around. Over time, the heap files will be vacuum frozen, and their relfrozenxid advanced. Once that happens to all heaps, the system thinks it can remove clog files, and doesn't realize the toast tables also need vacuuming. This is the "it might become more of a problem in the future" concern I have. The script I posted does fix this, and the code changes prevent it from happening completely. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
