pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Ivan Voras <ivoras@freebsd.org>
To: pgsql-performance@postgresql.org
Subject: Re: UPDATEDs slowing SELECTs in a fully cached database
Date: Tue, 12 Jul 2011 17:13:03 +0200
Message-ID: <ivho9v$6dp$1@dough.gmane.org> (raw)
In-Reply-To: <4E1B90AF.1020408@yahoo.com>
References: <4E16479D.3050605@yahoo.com>
	<4E1A0CBC.6090009@yahoo.com>
	<4E1A31AB.9010201@postnewspapers.com.au>
	<1310359653.80687.YahooMailRC@web121705.mail.ne1.yahoo.com>
	<4E1AEDAB020000250003F1C3@gw.wicourts.gov>
	<4E1B41EA.90104@yahoo.com>
	<4E1B05CC020000250003F1E6@gw.wicourts.gov>
	<CAHyXU0wPhZsQ_pMzfUWW0O=t_+2uwF-CJQNw-nuaxkjbi2zPEQ@mail.gmail.com>
	<4E1B810D.4070404@yahoo.com>
	<4E1B90AF.1020408@yahoo.com>

On 12/07/2011 02:09, lars wrote:

> Oh, and iowait hovers around 20% when SELECTs are slow:
>
> avg-cpu: %user %nice %system %iowait %steal %idle
> 1.54 0.00 0.98 18.49 0.07 78.92
>
> When SELECTs are fast it looks like this:
> avg-cpu: %user %nice %system %iowait %steal %idle
> 8.72 0.00 0.26 0.00 0.00 91.01
>
> Note that this is a 12 core VM. So one core at 100% would show as 8.33%
> CPU.

Now only if you could do an "iostat -x" and show the output in both cases...




view thread (57+ messages)  latest in thread

Message-ID: <ivho9v$6dp$1@dough.gmane.org>
Permalink:  ../ivho9v$6dp$1@dough.gmane.org/
Also on:    postgresql.org/message-id/ivho9v$6dp$1@dough.gmane.org

 · 

reply
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: ivoras@freebsd.org
  Subject: Re: UPDATEDs slowing SELECTs in a fully cached database
  In-Reply-To: <ivho9v$6dp$1@dough.gmane.org>

* 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