Re: 8.2 is 30% better in pgbench than 8.3

Tom,

> Note to all: we ***HAVE TO*** settle on some reasonable default
> vacuum_cost_delay settings before we can ship 8.3.  With no cost delay
> and two or three workers active, 8.3's autovac does indeed send
> performance into the tank.

I've been using 20ms for most of my setups.  That's aimed at reducing 
autovac to almost no impact at all, but taking a long time.  Maybe 10ms?

--Josh