Joe Conway wrote: > In my experience it is almost always best to run autovacuum very often > and very aggressively. That generally means tuning scaling factor and > thresholds as well, such that there are never more than say 50-100k dead > rows. Then running vacuum with no delays or limits runs quite fast is is > generally not noticeable/impactful. > > However that strategy does not work well for vacuums which run long, > such as an anti-wraparound vacuum. So in my opinion we need to think > about this as at least two distinct cases requiring different solutions.
With the freeze map there is no need for anti-wraparound vacuums to be terribly costly, since they don't need to scan the whole table each time. That patch probably changes things a lot in this area. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers