Re: [HACKERS] PATCH: multivariate histograms and MCV lists

From: Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>
To: Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com>
Cc: David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>, Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Michael Paquier <michael(at)paquier(dot)xyz>, Andres Freund <andres(at)anarazel(dot)de>, Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, Mark Dilger <hornschnorter(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [HACKERS] PATCH: multivariate histograms and MCV lists
Date: 2019-03-27 19:55:07
Message-ID: 20190327195507.GA21957@development
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I've now committed the MCV part, after addressing the last two issues
raised by Dean:

* The MCV build now always uses the mincount to decide which of the
items to keep in the list.

* Both the MCV build and deserialization now uses the same maximum number
of list items (10k).

Unfortunately, I forgot to merge these two fixes before pushing, so I had
to commit them separately. Sorry about that :/

Attached are the remaining parts of this patch series - the multivariate
histograms, and also a new patch tweaking regression tests for the old
statistic types (ndistinct, dependencies) to adopt the function-based
approach instead of the regular EXPLAIN.

But those are clearly a matter for the future (well, maybe it'd make sense
to commit the regression test change now).


Tomas Vondra
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Attachment Content-Type Size
0001-adopt-regression-tests.patch.gz application/gzip 3.1 KB
0002-multivariate-histograms.patch.gz application/gzip 48.4 KB

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