Re: performance problem with LIMIT (order BY in DESC order). Wrong index used? - Mailing list pgsql-performance

On Tue, Apr 12, 2011 at 10:59 AM, Dieter Rehbein
<dieter.rehbein@skiline.cc> wrote:
> I just executed a VACUUM ANALYZE and now everything performs well. hm, strange.

That probably means you need more statistics - try increasing the
newsfeed's statistics target count.

ALTER TABLE newsfeed_item ALTER COLUMN newsfeed SET STATISTICS <n>;

Try different <n> numbers, you can crank it up to 4000 or perhaps more
in 9.0, but you should start lower I guess.