Re: VERY slow after many updates

From: Guido Neitzer <guido(dot)neitzer(at)pharmaline(dot)de>
To: postgres performance list <pgsql-performance(at)postgresql(dot)org>
Cc: Alex Wang <alex(at)alexwang(dot)com>
Subject: Re: VERY slow after many updates
Date: 2005-11-19 12:18:19
Message-ID: AC098147-E4DC-4313-AFB3-196F1B81B96E@pharmaline.de
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On 19.11.2005, at 13:05 Uhr, Alex Wang wrote:

> Yes, it's a "queue" table. But I did not perform many insert/delete
> before it becomes slow. After insert 10 records, I just do get/
> update continuously.

When PostgreSQL updates a row, it creates a new row with the updated
values. So you should be aware, that the DB gets bigger and bigger
when you only update your rows. Vacuum full reclaims that used space.

The concepts are described in detail in the manual in chapter 12.

cug

--
PharmaLine Essen, GERMANY and
Big Nerd Ranch Europe - PostgreSQL Training, Dec. 2005, Rome, Italy
http://www.bignerdranch.com/classes/postgresql.shtml

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