Re: Speed question - new view using preview view components

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От Daniel Staal
Тема Re: Speed question - new view using preview view components
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Msg-id A665C78CF8F4E47CEFEA2044@mac-pro.magehandbook.com
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Ответ на Speed question - new view using preview view components  (richard terry <rterry@pacific.net.au>)
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--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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