Re: Wrong PostgreSQL Plan

On Tue, May 5, 2020 at 6:15 PM Virendra Kumar <viru_7683(at)yahoo(dot)com> wrote:

> Optimizer is behaving little weird in the sense that for change in one
> filter
>

You mean when you change the date equality filter to a more recent date?

> it is using NESTED LOOP JOIN and running for over 30 seconds whereas for
> other filter is working fine using HASH JOIN and under mili seconds.
>

Which means it runs to completion which means EXPLAIN ANALYZE is possible
and considerably more helpful.

We have played little bit around default_statistics_target, sometimes it
> worked when the setting is around 1500 other times it doesn't work even
> with setting as high as 5000. Is there anything community can suggest us in
> resolving this?
>

Given that adding more data causes the good plan to stop working I would
have to say that increasing how often you run ANALYZE on the table,
irrespective of default_statistics_target, is probably a good thing to try.

David J.