"Steve Wormley" <steve(at)wormley(dot)com> writes:
> Did a dump and restore of my DB to 8.1beta1 (running concurrently with
> 8.0.3) and performance on the same query is about 50% slower with the beta.
> Ran query twice on each instance in sequence to make sure all data was in OS
> cache.
Did you vacuum analyze (or at least analyze) both databases? The
rowcount estimates seem quite a bit different, which suggests the
two planners aren't working with the same stats.
regards, tom lane