Horton

Multivariate statistics and expression indexes

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2017-02-20T23:13:21Z
Lists: pgsql-hackers 
At the risk of asking a stupid question, we already have optimizer
statistics on expression indexes.  In what sense are we using this for
multi-variate statistics, and in what sense can't we.

FYI, I just wrote a blog post about expression index statistics:

	http://momjian.us/main/blogs/pgblog/2017.html#February_20_2017

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

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