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To: Mladen Gogala <mladen.gogala@vmsinfo.com>
cc: Eric Comeau <ecomeau@signiant.com>,
	"pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: Help with duration of statement: EXECUTE <unnamed> [PREPARE:
	COMMIT]
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Comments: In-reply-to Mladen Gogala <mladen.gogala@vmsinfo.com>
	message dated "Mon, 18 Oct 2010 10:25:17 -0400"
Date: Mon, 18 Oct 2010 11:02:15 -0400
Message-ID: <19782.1287414135@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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Mladen Gogala <mladen.gogala@vmsinfo.com> writes:
> Tom Lane wrote:
>> My guess would be overstressed disk subsystem.  A COMMIT doesn't require
>> much except fsync'ing the commit WAL record down to disk ... 

> Doesn't the "commit" statement also release all the locks held by the 
> transaction?

Yeah, and there's a nontrivial amount of other cleanup too, but it all
amounts to just changes in in-memory data structures.  I don't see that
taking five seconds, especially not if commits of similar transactions
usually take much less than that.

			regards, tom lane