Received: from magus.postgresql.org (magus.postgresql.org [87.238.57.229])
	by mail.postgresql.org (Postfix) with ESMTP id B6899C76A5A
	for <pgsql-performance@postgresql.org>;
	Sun, 26 Feb 2012 11:21:12 -0400 (AST)
Received: from li339-205.members.linode.com ([96.126.114.205]
	helo=squeakycode.net) by magus.postgresql.org with esmtp (Exim 4.72)
	(envelope-from <andy@squeakycode.net>) id 1S1fuQ-0007yK-8k
	for pgsql-performance@postgresql.org; Sun, 26 Feb 2012 15:21:11 +0000
Received: from [192.168.1.116] (50-83-220-125.client.mchsi.com
 [50.83.220.125])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(No client certificate requested) (Authenticated sender: andy)
	by squeakycode.net (Postfix) with ESMTPSA id BA27416890;
	Sun, 26 Feb 2012 10:20:55 -0500 (EST)
Message-ID: <4F4A4DD6.6090904@squeakycode.net>
Date: Sun, 26 Feb 2012 09:20:54 -0600
From: Andy Colson <andy@squeakycode.net>
User-Agent: Mozilla/5.0 (X11; Linux i686;
	rv:10.0) Gecko/20120131 Thunderbird/10.0
MIME-Version: 1.0
To: Stefan Keller <sfkeller@gmail.com>
CC: pgsql-performance@postgresql.org, Stephen Frost <sfrost@snowman.net>
Subject: Re: PG as in-memory db? How to warm up and re-populate
	buffers? How to read in all tuples into memory?
References: 
 <CAFcOn28A3dkmCEGsu-7Chi0gH1qAPYcfbSp8op9gswFawS6ECA@mail.gmail.com>
In-Reply-To: 
 <CAFcOn28A3dkmCEGsu-7Chi0gH1qAPYcfbSp8op9gswFawS6ECA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Pg-Spam-Score: -1.9 (-)
X-Archive-Number: 201202/212
X-Sequence-Number: 46384

On 02/25/2012 06:16 PM, Stefan Keller wrote:
>
> 1. How can I warm up or re-populate shared buffers of Postgres?
> 2. Are there any hints on how to tell Postgres to read in all table
> contents into memory?
>
> Yours, Stefan
>

How about after you load the data, vacuum freeze it, then do something like:

SELECT count(*) FROM osm_point WHERE tags @> 'tourism=>junk'

-Andy