Re: Datatypes and performance - Mailing list pgsql-general

From Dennis Björklund
Subject Re: Datatypes and performance
Date
Msg-id Pine.LNX.4.44.0307050711440.1516-100000@zigo.dhs.org
Whole thread Raw
In response to Re: Datatypes and performance  ("Maksim Likharev" <mlikharev@aurigin.com>)
List pgsql-general
On Fri, 4 Jul 2003, Maksim Likharev wrote:

> Ok, then if I store 4K - 1byte in a varchar and after that 4K + 1 byte,
> and again and again, you are saying me that my text will be jerking
> around 2 tables?

Updates in postgresql is not done inplace. It just adds the new data and
the old is kept around so that other concurrent transactions can still run
and use the old data. This gives a lot of speed when you have many
concurrent users.

Vacuum cleans out old unused data.

--
/Dennis


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