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Re: Speed question - new view using preview view components

From: Daniel Staal <DStaal(at)usa(dot)net>
To: pgsql-novice <pgsql-novice(at)postgresql(dot)org>
Subject: Re: Speed question - new view using preview view components
Date: 2010-03-21 01:55:22
Message-ID: A665C78CF8F4E47CEFEA2044@mac-pro.magehandbook.com (view raw or flat)
Thread:
Lists: pgsql-novice
--As of March 21, 2010 12:23:19 PM +1100, richard terry is alleged to have 
said:

> I wondered if when creating a new view from multiple tables, and then
> also  joining to some fields of an existing view, if one pays much of a
> speed  penalty when the data is retrieved, as opposed to just completely
> using all  tables.

--As for the rest, it is mine.

First off, to help you answer your question (and others like it in the 
future) yourself:
<http://www.postgresql.org/docs/8.4/interactive/sql-explain.html>

Which I believe will tell you that there is no difference as far as 
Postgres is concerned.  It will see the two selects (assuming they actually 
have the same structure) exactly the same: The view only makes it easier to 
write the first.  (At least in this use.)

Daniel T. Staal

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