From: Kevin Grittner <Kevin.Grittner@wicourts.gov>
To: pgsql-performance@postgresql.org
To: brauagustin-susc@yahoo.com.ar
Subject: Re: Low CPU Usage
Date: Fri, 21 Sep 2007 12:51:57 -0500
Message-ID: <46F3BE6C.EE98.0025.0@wicourts.gov> (raw)
In-Reply-To: <121711.47531.qm@web30006.mail.mud.yahoo.com>
References: <121711.47531.qm@web30006.mail.mud.yahoo.com>
>>> 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:
> This is the plan for the old server:
> Hash Join (cost=449.55..8879.24 rows=136316 width=904) (actual
> time=50.734..1632.491 rows=136316 loops=1)
. . .
> Total runtime: 2022.293 ms
> And this is the plan for the new server:
> Hash Join (cost=412.86..9524.13 rows=136316 width=905) (actual
> time=9.421..506.376 rows=136316 loops=1)
. . .
> Total runtime: 553.619 ms
> I see an "outer" join in the plan for the new server. This is weird!!! There
> are the same databases in both servers.
That's just a matter of labeling the tables with role rather than alias.
The plans look the same to me.
> The old one runs this query for about 37 seconds and for the new one for
> about 301 seconds.
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?
-Kevin
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: Kevin.Grittner@wicourts.gov, brauagustin-susc@yahoo.com.ar
Subject: Re: Low CPU Usage
In-Reply-To: <46F3BE6C.EE98.0025.0@wicourts.gov>
* 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