On 1 Nov 2012, at 17:44, Shaun Thomas wrote: > On 11/01/2012 11:40 AM, Alban Hertroys wrote: > >> Instead of attempting to postpone freeze until beyond the life >> expectancy of our universe, what you probably should have done is >> vacuum more often so that vacuum has less work to do. > > More often than every night, with autovacuum running in the background to get > regular stuff that happens during the day? 650M transactions is 3 or 4 days > for us. That's hardly the lifetime of the universe. And since I didn't modify > vacuum_freeze_table_age, any table vacuumed after 150M transactions is given > a vacuum freeze anyway. No harm done.
150M database transactions a day sounds excessive, is there no way to reduce that number? That aside, 650M transactions in 3 at 4 days is not equal to 150M transactions a day. It can be quite a few more. Since you mentioned that the market halted for 2 days there were probably a lot more transactions waiting than usual; not just piled up work, but lots of attempts at corrections as well. It wouldn't surprise me if you went over 650M transactions that day. > It's my understanding you *don't* want to freeze excessively. I think once > every day is bad enough, honestly. That's not what I was suggesting. I wasn't talking about vacuum freeze but normal autovacuum with more aggressive parameters. That should handle transaction wrap-around automatically when it looks like you're getting close to the transaction wrap-around id. As per the docs in 8.2, vacuum freeze was deprecated back then already. Knowing the devs a bit, there was a good reason to do so. Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll find there is no forest. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
