Re: performance - self-joins vs. subqueries

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От K. Ari Krupnikov
Тема Re: performance - self-joins vs. subqueries
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Msg-id 3A888331.6DF45B27@iln.net
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Ответ на performance - self-joins vs. subqueries  ("K. Ari Krupnikov" <ari@iln.net>)
Ответы Re: performance - self-joins vs. subqueries  (Tom Lane <tgl@sss.pgh.pa.us>)
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Tom Lane wrote:
>
> "K. Ari Krupnikov" <ari@iln.net> writes:
> > Many queries can be formulated as either a self-join or a subquery on
> > the same table.
> > Is there any difference in performance, or does the analyzer treat them
> > the same?
>
> You're a lot better off with a self-join, at present.

At present - is there a change planned?

Could you elaborate a little on how such queries are expanded?

--
K. Ari Krupnikov

DBDOM - bridging XML and relational databases
http://www.iter.co.il

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