Re: How efficient are Views

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От Henshall, Stuart - WCP
Тема Re: How efficient are Views
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Msg-id E2870D8CE1CCD311BAF50008C71EDE8E01F748E7@MAIL_EXCHANGE
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Ответ на How efficient are Views  (John Taylor <postgres@jtresponse.co.uk>)
Список pgsql-novice

Everytime the view is accessed the query is executed.
- Stuart

> -----Original Message-----
> From: John Taylor [mailto:postgres@jtresponse.co.uk]
>
> On Wednesday 12 June 2002 16:21, you wrote:
>
> > > A view just re-executes the query.
> > Therefore a view is as efficient as the query it's based upon :)
> > hth,
>
> But, does the query get processed, every time the view is
> accessed, or whenever
> the underlying data is changed ?
>
> If it is the former, then it would be the same as using a subselect:
> SELECT * FROM (SELECT my view query) WHERE blah ...
>
> Thanks
> JohnT
>

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