Skip site navigation (1) Skip section navigation (2)

Re: Queries becoming slow under heavy load

From: "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>
To: "Anne Rosset" <arosset(at)collab(dot)net>, <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Queries becoming slow under heavy load
Date: 2011-01-25 22:12:24
Message-ID: 4D3EF6680200002500039CA0@gw.wicourts.gov (view raw or flat)
Thread:
Lists: pgsql-performance
"Anne Rosset" <arosset(at)collab(dot)net> wrote:
 
> We are running some performances tests.  With a lot of concurrent
> access, queries get very slow. When there is no load, those
> queries run fast.
 
What's "a lot"?
 
> We kind of see a trend about these queries:  it seems like the
> ones that become very slow have an ORDER BY or MAX in them.
 
Without knowing the PostgreSQL version or more details about the
queries, I would only be guessing at the cause.
 
> It seems to me that we should try increasing shared_buffers. But
> do you have any other suggestions? Or do you see anything wrong in
> our config?
 
I don't think you showed us your whole PostgreSQL configuration, and
the format was hard to read -- it's best to show the contents of
your postgresql.conf file, minus comments.
 
If you read this page and re-post we can probably be more helpful:
 
http://wiki.postgresql.org/wiki/SlowQueryQuestions
 
-Kevin

In response to

pgsql-performance by date

Next:From: Andy ColsonDate: 2011-01-25 22:12:45
Subject: Re: Queries becoming slow under heavy load
Previous:From: Anne RossetDate: 2011-01-25 21:37:54
Subject: Queries becoming slow under heavy load

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group