On 2013-06-02 11:44:04 -0700, Jeff Janes wrote:
> Do we know why anti-wraparound uses so many resources in the first place?
> The default settings seem to be quite conservative to me, even for a
> system that has only a single 5400 rpm hdd (and even more so for any real
> production system that would be used for a many-GB database).
I guess the point is that nobody can actually run a bigger OLTP database
successfully with the default settings. Usually that will end up with a)
huge amounts of bloat in the tables autovac doesn't scan first b) forced
shutdowns because autovac doesn't freeze quickly enough.
The default suggestion that frequently seems to be made is just to
disable autovac cost limitations because of that.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services