Re: [HACKERS] subselect and optimizer
Igor Sysoev <igor@nitek.ru>
From: "Igor Sysoev" <igor@nitek.ru>
To: <pgsql-hackers@postgresql.org>
Date: 1998-04-22T07:36:23Z
Lists: pgsql-hackers
Vadim wrote: > BTW, IN is slow (currently :) - try to create 2-key index on bik (bik, newkey) > and rewrite your query as > > select * from bik b1 where EXISTS (select newkey from bik where > bik = '....' and b1.key = newkey) > > And let's know... (Note, that index on (newkey, bik) may be more useful > than on (bik, newkey) - it depends on your data). I had tried - it really works ! I don't even try to use index for bik (bik). It works even when I tried "bik ~ '...'". The one downside is I need to crunch and twist my brains to use such SQL statemants :). Thank you. Igor Sysoev