Re: Subquery in a JOIN not getting restricted?

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От Kevin Grittner
Тема Re: Subquery in a JOIN not getting restricted?
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Msg-id 4EBA8C100200002500042C23@gw.wicourts.gov
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Ответ на Re: Subquery in a JOIN not getting restricted?  (Merlin Moncure <mmoncure@gmail.com>)
Ответы Re: Subquery in a JOIN not getting restricted?  (Jay Levitt <jay.levitt@gmail.com>)
Список pgsql-performance
Merlin Moncure <mmoncure@gmail.com> wrote:

> Well, this may not fit the OP's 'real' query

Right, if I recall correctly, the OP said it was simplified down as
far as it could be and still have the issue show.

> but the inner subquery is probably better written as a semi-join
> (WHERE EXISTS).

Well, that doesn't mean that we shouldn't try to optimize perfectly
valid alternative spellings.  Having each logically equivalent way
to write a query generate a different plan is far worse than hints
that are more clearly written.  ;-)

-Kevin

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