indexed column but queries still slow

From: Amir Zicherman <amir(dot)zicherman(at)gmail(dot)com>
To: pgsql-novice(at)postgresql(dot)org
Subject: indexed column but queries still slow
Date: 2004-08-17 21:06:11
Message-ID: 27a5b7d104081714064cc9cd0c@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-novice

hi,

i have a btree index on col1 in table1. The column has either values
1,2,3, or 4. 4 does not appear that much in the table (only 5 times).
there are about 20 million rows in the table. when i do a "select *
from table1 where col1=4" it takes very long time to get back to me
(around 4 minutes). why is it taking so long if i have an index on
it? I also tried this with a hash index and it was still slow.

thanx, amir

Responses

Browse pgsql-novice by date

  From Date Subject
Next Message Gaetano Mendola 2004-08-17 23:28:29 Re: indexed column but queries still slow
Previous Message Tom Lane 2004-08-17 19:48:47 Re: pg_attribute has way too many row versions