Re: select distinct, index not used

From: Grzegorz Jaśkiewicz <gryzman(at)gmail(dot)com>
To: Thomas Guettler <hv(at)tbz-pariv(dot)de>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: select distinct, index not used
Date: 2009-04-16 15:27:32
Message-ID: 2f4958ff0904160827r32200bb1ub8d73227480a5de9@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

wasn't that improved now in 8.4, and before that on 8.3 ?
still there are some funny things with distinct/group by .
for instance, try
select count(distinct foo) from bar; vs
select count(1) from (select distinct foo from bar) f;

:)

I am not sure it pg was able to use index for that in 8.2.

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Tom Lane 2009-04-16 15:29:25 Re: select distinct, index not used
Previous Message David Fetter 2009-04-16 15:21:38 Re: [GENERAL] Performance of full outer join in 8.3