Date: Thu, 28 Sep 2006 13:40:24 -0400
From: Bill Moran <wmoran@collaborativefusion.com>
To: "Jim C. Nasby" <jim@nasby.net>
Cc: Matthew Schumacher <matt.s@aptalaska.net>,
 pgsql-performance@postgresql.org
Subject: Re: Problems with inconsistant query performance.
Message-Id: <20060928134024.bf09db28.wmoran@collaborativefusion.com>
In-Reply-To: <20060928161549.GN34238@nasby.net>
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In response to "Jim C. Nasby" <jim@nasby.net>:

> On Thu, Sep 28, 2006 at 11:28:43AM -0400, Bill Moran wrote:
> > In response to Matthew Schumacher <matt.s@aptalaska.net>:
> > > 
> > > What I really need is a way to profile my proc when it runs slow so that
> > > I can resolve which of the queries is really slow.  Anyone with an idea
> > > on how to do this?
> > 
> > You could turn on statement logging and duration logging.  This would
> > give you a record of when things run and how long they take.  A little
> > work analyzing should show you which queries are running when your
> > favorite query slows down.
> 
> By default, that doesn't help you debug what's happening inside a
> function, because you only get the call to the function. I don't know if
> you can increase verbosity to combat that.

Right, but my point was that he believes another query is interfering
when the target query is slow.  Turning on those logging statements
will:
a) Allow him to identify times when the query is slow.
b) Identify other queries that are running at the same time.

If he sees a pattern (i.e. My query is always slow if query X5 is
running at the same time) he'll have a good lead into further research.

-- 
Bill Moran
Collaborative Fusion Inc.