Alvaro Herrera <alvherre@xxxxxxxxxxxxxxxxx> writes: > Casey Duncan wrote: >> I'm curious how template0 got stomped on. > Heh :-) Sorry, they are all my bugs. I guess you should be throwing > stones at me or something. The pre-8.1 theory was that template0 is (supposed to be) cleanly frozen and hence never needs vacuumed at all. The post-8.1 theory is that template0 gets autovacuumed when necessary to prevent wraparound, just like every other database. 8.1 unfortunately is somewhere in the middle, because under circumstances-I-don't-remember-at-the-moment, autovacuum might decide to process template0 and then leave non-frozen XIDs therein. Which is a problem because the clog-truncation logic didn't think it needed to consider template0 when deciding if old clog segments could be thrown away. We live and learn. The real bottom line here, and one I'll reiterate every chance I get, is that we don't make updates to back branches because we're too bored to have anything else to do. If you're on 8.1.5, and the current release in that branch is 8.1.8, then you're missing some bug fixes that are probably significant. regards, tom lane
