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From: Alvaro Herrera <alvherre@commandprompt.com>
To: Matthew Wakeling <matthew@flymine.org>
Cc: pgsql-performance@postgresql.org
Subject: Re: I/O on select count(*)
Date: Thu, 15 May 2008 11:52:32 -0400
Message-ID: <20080515155232.GC8221@alvh.no-ip.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0805151245360.16756@aragorn.flymine.org>
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	<Pine.LNX.4.64.0805151245360.16756@aragorn.flymine.org>

Matthew Wakeling wrote:

Aside from the rest of commentary, a slight clarification:

> So, as I understand it, Postgres works like this:
>
> 1. You begin a transaction. Postgres writes an entry into pg_clog.

Starting a transaction does not write anything to pg_clog.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

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