> On further reflection, though: since we put in the BufferAccessStrategy > code, which was in 8.3, the background writer isn't *supposed* to be > very much involved in writing pages that are dirtied by VACUUM. VACUUM > runs in a small ring of buffers and is supposed to have to clean its own > dirt most of the time. So it's wrong to blame this on the bgwriter not > holding up its end. Rather, what you need to be thinking about is how > come vacuum seems to be making lots of pages dirty on only one of these > machines.
This is an anti-wraparound vacuum, so it could have something to do with the hint bits. Maybe it's setting the freeze bit on every page, and writing them one page at a time? Still don't understand the call to pollsys, even so, though. -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers