Re: BUG #1851: Performance reduction from 8.0.3

On 2005-08-26 16:17, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> "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.
>

Sigh, I swore I remembered to at least analyze both, but I guess not. After
vacuum analyze 8.1beta1 is fine and happy and using a virtually identical
plan and coming in a few hundred milliseconds faster.

Thanks,
-Steve Wormley