Hannes Erven <hannes@xxxxxxxx> writes: > On 2014-04-27 21:53, Tom Lane wrote: >> Sitting on an open transaction for hours would be a bad idea. > I'm wondering why this is and what the consequences might be - I > thought, the MVCC model would handle that rather well? Vacuum can't delete dead rows if there's some transaction that can still see them. So long-running transactions + update activity = table bloat. (I had the idea that we'd fixed this, in recent releases, if you're using READ COMMITTED isolation level; but some experimentation says VACUUM still won't release rows while there are idle transactions.) regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
