Horton

Re: multivariate statistics (v19)

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, ideriha.takeshi@jp.fujitsu.com, dilipbalaut@gmail.com, Langote_Amit_f8@lab.ntt.co.jp, dean.a.rasheed@gmail.com, hlinnaka@iki.fi, robertmhaas@gmail.com, ishii@postgresql.org, david@pgmasters.net, michael.paquier@gmail.com, tgl@sss.pgh.pa.us, petr@2ndquadrant.com, jeff.janes@gmail.com, pgsql-hackers@postgresql.org
Date: 2017-02-07T00:38:14Z
Lists: pgsql-hackers 
Still about 0003.  dependencies.c comment at the top of the file should
contain some details about what is it implementing and a general
description of the algorithm and data structures.  As before, it's best
to have the main entry point build_mv_dependencies at the top, the other
public functions, keeping the internal routines at the bottom of the
file.  That eases code study for future readers.  (Minimizing number of
function prototypes is not a goal.)

What is MVSTAT_DEPS_TYPE_BASIC?  Is "functional dependencies" really
BASIC?  I wonder if it should be TYPE_FUNCTIONAL_DEPS or something.

As with pg_ndistinct_out, there's no need to pstrdup(str.data), as it's
already palloc'ed in the right context.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Collect and use multi-column dependency stats

  2. Implement SortSupport for macaddr data type

  3. Implement multivariate n-distinct coefficients

  4. Generate fmgr prototypes automatically