Message-ID: <4F467FCD.8090100@peak6.com>
Date: Thu, 23 Feb 2012 12:05:01 -0600
From: Shaun Thomas <sthomas@peak6.com>
Reply-To: <sthomas@peak6.com>
Organization: Peak6
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To: Greg Spiegelberg <gspiegelberg@gmail.com>
CC: "Reuven M. Lerner" <reuven@lerner.co.il>, Andrew Dunstan
	<andrew@dunslane.net>,
	=?UTF-8?B?TWFyY2luIE1hxYRr?= <marcin.mank@gmail.com>,
	<pgsql-performance@postgresql.org>
Subject: Re: Very long deletion time on a 200 GB database
References: <4F45FB55.1020600@lerner.co.il>
	<CAK61fk6bSQtmDUzm2rNv33kN4Oar_dYZ-yFEa9zR_zLL8L9esQ@mail.gmail.com>
	<4F464C49.4050503@dunslane.net> <4F465A7A.4000905@lerner.co.il>
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On 02/23/2012 11:56 AM, Greg Spiegelberg wrote:

> I know there are perils in using ctid but with the LOCK it should be
> safe. This transaction took perhaps 30 minutes and removed 100k rows
> and once the table was VACUUM'd afterward it freed up close to 20 GB
> on the file system.

It took *30 minutes* to delete 100k rows? And 100k rows were using 20GB? 
Is that off by an order of magnitude?

Using the ctid is a cute trick, though. :)

-- 
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 500 | Chicago IL, 60604
312-444-8534
sthomas@peak6.com

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