Re: 7.4 - FK constraint performance

On Thu, 12 Feb 2004, ow wrote:

> --- Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com> wrote:
> > You also did the alter table to up the statistics target on the column,
> > right?
>
> Not really. I did not change the the default stats settings in the
> postgresql.conf. Not sure what needs to be changed, can you clarify?

Basically, run something like:
-- 1000 is just an arbitrary choice, but we can lower it later if this
-- works.
ALTER TABLE my.Large ALTER COLUMN small_id SET STATISTICS 1000;
ANALYZE my.Large;

This increases the target for just the column in question which means it
should have a better idea of the distribution and may make it make a
better guess if you've got a somewhat uneven distribution.