Re: Final Patch for GROUPING SETS - unrecognized node type: 347

From: Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk>
To: Tomas Vondra <tv(at)fuzzy(dot)cz>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Final Patch for GROUPING SETS - unrecognized node type: 347
Date: 2014-09-10 16:16:21
Message-ID: 87iokv4g2y.fsf@news-spur.riddles.org.uk
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>>>>> "Tomas" == Tomas Vondra <tv(at)fuzzy(dot)cz> writes:

Tomas> If we can get rid of the excessive ChainAggregate, that's
Tomas> 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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