Date: Mon, 20 Jun 2005 09:56:31 +0200
From: David Pradier <dpradier@apartia.fr>
To: Michael Glaesemann <grzm@myrealbox.com>
Cc: postgresql sql list <pgsql-sql@postgresql.org>
Subject: Re: UPDATEABLE VIEWS ... Examples?
Message-ID: <20050620075631.GD15942@apartia.fr>
References: <20050616180356.Y90456@ganymede.hub.org>
	<20050620071604.GB15942@apartia.fr>
	<3E0EA84A-7A3B-4BDC-ADB2-08D664551CD8@myrealbox.com>
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> >This is maybe a newbie question, but what is the difference with a
> >materialized view ?
> 
> As I understand it (and that understanding may be wrong) a  
> materialized view is a table that holds the values of a view from  
> some point in time. A view is a "saved" subselect. Everything you  
> call a view, the PostgreSQL backend re-evaluates the definition of  
> the view. A materialized view is only as accurate as the last time it  
> was updated. Things such as triggers can be used to keep the  
> materialized view updated. The key issue with materialized views is  
> to make sure it's always up-to-date with the evaluation of the view.

Thanks Michael, I already know what is a materialized view. I often use
them, systematically updated with some triggers.
It's an updatable view that i didn't knew.

It opens some perspectives in programmation, methinks :-)

Thanks all the same,
David

-- 
dpradier@apartia.fr - tel: 01.46.47.21.33 - fax: 01.46.47.21.37