Re: Final Patch for GROUPING SETS - unrecognized node type: 347 - Mailing list pgsql-hackers

From Andrew Gierth
Subject Re: Final Patch for GROUPING SETS - unrecognized node type: 347
Date
Msg-id 87iokv4g2y.fsf@news-spur.riddles.org.uk
Whole thread Raw
In response to Re: Final Patch for GROUPING SETS - unrecognized node type: 347  (Tomas Vondra <tv@fuzzy.cz>)
Responses Re: Final Patch for GROUPING SETS  (Andrew Gierth <andrew@tao11.riddles.org.uk>)
List pgsql-hackers
>>>>> "Tomas" == Tomas Vondra <tv@fuzzy.cz> writes:
Tomas> If we can get rid of the excessive ChainAggregate, that'sTomas> certainly enough for now.

I found an algorithm that should provably give the minimal number of sorts
(I was afraid that problem would turn out to be NP-hard, but not so - it's
solvable in P by reducing it to a problem of maximal matching in bipartite
graphs).

Updated patch should be forthcoming in a day or two.

-- 
Andrew (irc:RhodiumToad)



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