Thread: Are views created 'on the fly'

Are views created 'on the fly'

From
richard terry
Date:
I had an occasion to generate a unique key on a complex view and noticed that
every time I opened the view in pgAdmin, that the start key changes, does
that mean that every time one references a view it is created 'on the fly',
before you query it for data?

regards

Richard

Re: Are views created 'on the fly'

From
Andreas Kretschmer
Date:
richard terry <rterry@pacific.net.au> wrote:

> I had an occasion to generate a unique key on a complex view and noticed that
> every time I opened the view in pgAdmin, that the start key changes, does
> that mean that every time one references a view it is created 'on the fly',
> before you query it for data?

A VIEW is nothing else than a stored query. Every time you query the
VIEW, your query is replaced by the definition of the view.

You need a unique key on that view? Well, you can use PG 8.4 and its
build-in row_number(() - function.


Andreas
--
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect.                              (Linus Torvalds)
"If I was god, I would recompile penguin with --enable-fly."   (unknown)
Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°

Re: Are views created 'on the fly'

From
richard terry
Date:
On Sun, 5 Jul 2009 04:00:18 pm Andreas Kretschmer wrote:
> richard terry <rterry@pacific.net.au> wrote:
> > I had an occasion to generate a unique key on a complex view and noticed
> > that every time I opened the view in pgAdmin, that the start key changes,
> > does that mean that every time one references a view it is created 'on
> > the fly', before you query it for data?
>
> A VIEW is nothing else than a stored query. Every time you query the
> VIEW, your query is replaced by the definition of the view.
>
> You need a unique key on that view? Well, you can use PG 8.4 and its
> build-in row_number(() - function.
>
>
> Andreas
> --
> Really, I'm not out to destroy Microsoft. That will just be a completely
> unintentional side effect.                              (Linus Torvalds)
> "If I was god, I would recompile penguin with --enable-fly."   (unknown)
> Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°

thanks.

Richard