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

From Dimitri Fontaine
Subject Re: Optimization rules for semi and anti joins
Date
Msg-id FAEBF2D0-40DA-434D-92D2-3DDB33F8B357@hi-media.com
Whole thread Raw
In response to Optimization rules for semi and anti joins  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Optimization rules for semi and anti joins
List pgsql-hackers
Hi,

Le 10 févr. 09 à 21:10, Tom Lane a écrit :

> 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?

I don't know how easy it would be to do, but maybe the Coq formal
proof management system could help us here:  http://coq.inria.fr/

The harder part in using coq might well be to specify the problem the
way you just did, so...

HTH,
--
dim





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