Message-Id: <46F3BE6C.EE98.0025.0@wicourts.gov>
Date: Fri, 21 Sep 2007 12:51:57 -0500
From: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>
To: <pgsql-performance@postgresql.org>,<brauagustin-susc@yahoo.com.ar>
Subject: Re: Low CPU Usage
References: <121711.47531.qm@web30006.mail.mud.yahoo.com>
In-Reply-To: <121711.47531.qm@web30006.mail.mud.yahoo.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

>>> On Fri, Sep 21, 2007 at 12:30 PM, in message
<121711.47531.qm@web30006.mail.mud.yahoo.com>, <brauagustin-susc@yahoo.com.=
ar>
wrote:=20
=20
> This is the plan for the old server:
> Hash Join  (cost=3D449.55..8879.24 rows=3D136316 width=3D904) (actual=20
> time=3D50.734..1632.491 rows=3D136316 loops=3D1)
. . .
> Total runtime: 2022.293 ms
=20
> And this is the plan for the new server:
> Hash Join  (cost=3D412.86..9524.13 rows=3D136316 width=3D905) (actual=20
> time=3D9.421..506.376 rows=3D136316 loops=3D1)
. . .
> Total runtime: 553.619 ms
=20
> I see an "outer" join in the plan for the new server. This is weird!!! =
There=20
> are the same databases in both servers.
=20
That's just a matter of labeling the tables with role rather than alias.
The plans look the same to me.
=20
> The old one runs this query for about 37 seconds and for the new one =
for=20
> about 301 seconds.
=20
That's not what it looks like based on the EXPLAIN ANALYZE output.
It looks like run time dropped from two seconds to half a second.
=20
It seems as though you either have a network delay delivering the results,
or your application is slow to read them.

Exactly how are you arriving at those timings you're reporting to us?
=20
-Kevin
=20