Message-ID: <43983945.9020706@opusvl.com>
Date: Thu, 08 Dec 2005 13:46:45 +0000
From: Rich Doughty <rich@opusvl.com>
Organization: Opus VL
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To: KeithW@NarrowPathInc.com
CC: PostgreSQL Perform <pgsql-performance@postgresql.org>
Subject: Re: view of view
References: <43979EC0.1060400@NarrowPathInc.com>
In-Reply-To: <43979EC0.1060400@NarrowPathInc.com>
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Keith Worthington wrote:
> Hi All,
> 
> I am working on an application that uses PostgreSQL.  One of the 
> functions of the application is to generate reports.  In order to keep 
> the code in the application simple we create a view of the required data 
> in the database and then simply execute a SELECT * FROM 
> view_of_the_data;  All of the manipulation and most of the time even the 
> ordering is handled in the view.
> 
> My question is how much if any performance degradation is there in 
> creating a view of a view?
> 
> IOW if I have a view that ties together a couple of tables and 
> manipulates some data what will perform better; a view that filters, 
> manipulates, and orders the data from the first view or a view that 
> performs all the necessary calculations on the original tables?

from personal experience, if the inner views contain outer joins performance
isn't that great.

-- 

   - Rich Doughty