From: Bill Moran <wmoran@collaborativefusion.com>
To: brauagustin-susc@yahoo.com.ar
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-performance@postgresql.org
Subject: Re: Low CPU Usage
Date: Fri, 21 Sep 2007 14:33:54 -0400
Message-ID: <20070921143354.3d35cbff.wmoran@collaborativefusion.com> (raw)
In-Reply-To: <582823.746.qm@web30009.mail.mud.yahoo.com>
References: <582823.746.qm@web30009.mail.mud.yahoo.com>
In response to brauagustin-susc@yahoo.com.ar:
> > 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.
>
> > 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?
>
> I have noticed this in a daly process I run which involves normally 45 minutes and with the new server takes 1:40.
>
> Some days ago I began to do some tests with no success, then I opened PgAdmin with this simply query to read 2 big tables and then compare disk access.
> SELECT *
> FROM fact_ven_renta fvr, dim_producto_std_producto dpp
> WHERE
> fvr.producto_std_producto_sk = dpp.producto_sk
>
> fact_ven_renta has 136316 rows
> dim_producto_std_producto has 3669 rows
Run the tests from psql on the same server. As Kevin pointed out, the
_server_ is faster, but it appears as if the connection between PGadmin
and this new server is slower somehow.
Are you sure of your speed/duplex settings on the network side? That's
the most common cause of this kind of thing in my experience. Try doing
a raw FTP transfer between the client and server and see if you get the
speed you should.
>
>
>
> I have made all possible combinations pgadmin (running in the same server each query, in the old one, in the new one), without difference and I only retrieve the first 100 records (I didn't count the network time in any case).
> But the weird thing is running the query in the new server the are many disk access and cpu usage. And with other applications in the same server are a lot of disks access.
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran@collaborativefusion.com
Phone: 412-422-3463x4023
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: wmoran@collaborativefusion.com, brauagustin-susc@yahoo.com.ar, Kevin.Grittner@wicourts.gov
Subject: Re: Low CPU Usage
In-Reply-To: <20070921143354.3d35cbff.wmoran@collaborativefusion.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox