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Re: Optimization rules for semi and anti joins - Mailing list pgsql-hackers

From Jonah H. Harris
Subject Re: Optimization rules for semi and anti joins
Date
Msg-id 36e682920902101712w3bc22c18t703f5b2d84e21f94@mail.gmail.com
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In response to Re: Optimization rules for semi and anti joins  ("Jonah H. Harris" <jonah.harris@gmail.com>)
Responses Re: Optimization rules for semi and anti joins  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Optimization rules for semi and anti joins  (David Fetter <david@fetter.org>)
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On Tue, Feb 10, 2009 at 8:09 PM, Jonah H. Harris <jonah.harris@gmail.com> wrote:
On Tue, Feb 10, 2009 at 3:10 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
I wrote (in response to Kevin Grittner's recent issues):
> Reflecting on this further, I suspect there are also some bugs in the
> planner's rules about when semi/antijoins can commute with other joins;

After doing some math I've concluded this is in fact the case.  Anyone
want to check my work?

FWIW, the logic looks correct to me.

Cripes!  I just had an idea and it looks like the buggers beat me to it :(

http://www.google.com/patents?id=4bqBAAAAEBAJ&dq=null+aware+anti-join

--
Jonah H. Harris, Senior DBA
myYearbook.com

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