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Re: Automatic optimization of IN clauses via INNER JOIN - Mailing list pgsql-performance

From Grzegorz Jaśkiewicz
Subject Re: Automatic optimization of IN clauses via INNER JOIN
Date
Msg-id 2f4958ff0912180624v48f8b23cyf4c218d41f80e145@mail.gmail.com
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In response to Re: Automatic optimization of IN clauses via INNER JOIN  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Automatic optimization of IN clauses via INNER JOIN  (Robert Haas <robertmhaas@gmail.com>)
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On Fri, Dec 18, 2009 at 2:18 PM, Robert Haas <robertmhaas@gmail.com> wrote:

> NOT IN is the only that really kills you as far as optimization is
> concerned.  IN can be transformed to a join.  NOT IN forces a NOT
> (subplan)-type plan, which bites - hard.

in a well designed database (read: not abusing NULLs) - it can be done
with joins too.



--
GJ

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