Re: Postgres not using indexes

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: "pgsql-bugs(at)postgresql(dot)org" <pgsql-bugs(at)postgresql(dot)org>, "Lawrence Cohan" <LCohan(at)web(dot)com>
Subject: Re: Postgres not using indexes
Date: 2011-03-30 16:45:23
Message-ID: 4D9317D3020000250003BF7B@gw.wicourts.gov
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

Lawrence Cohan <LCohan(at)web(dot)com> wrote:

> We have a huge performance issues in Postgres that surfaced due to
> existing indexes not being used

This doesn't sound like a bug; it sounds like you haven't tuned your
server.

For starters, you should check out this page:

http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server

As a quick try, you could issue these statements on the connection
right before one of the problem queries:

set effective_cache_size = '7GB';
-- use 1 or 2 GB less than RAM on the machine
set random_page_cost = 2;
-- now try your query

If, after reading the above-cited page and tuning your server you
still have performance problems, pick one query to work on first,
and follow the step outlined here:

http://wiki.postgresql.org/wiki/SlowQueryQuestions

Use the pgsql-performance list for performance issues, not the bugs
list. You'll find more people who will be able to help you with
performance issues there.

-Kevin

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Lawrence Cohan 2011-03-30 16:51:17 Re: Postgres not using indexes
Previous Message Lawrence Cohan 2011-03-30 16:13:42 Re: Postgres not using indexes