Horton

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

Mark Dilger <hornschnorter@gmail.com>

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From: Mark Dilger <hornschnorter@gmail.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: Adrien Nayrat <adrien.nayrat@dalibo.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2017-11-25T20:25:49Z
Lists: pgsql-hackers 
> On Nov 18, 2017, at 12:28 PM, Tomas Vondra <tomas.vondra@2ndquadrant.com> wrote:
> 
> Hi,
> 
> Attached is an updated version of the patch, adopting the psql describe
> changes introduced by 471d55859c11b.
> 
> regards
> 
> -- 
> Tomas Vondra                  http://www.2ndQuadrant.com
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
> <0001-multivariate-MCV-lists.patch.gz><0002-multivariate-histograms.patch.gz>

In src/backend/statistics/mcv.c, you have a few typos:

+ * there bo be a lot of duplicate values. But perhaps that's not true and we

+       /* Now it's safe to access the dimention info. */

+        * Nowe we know the total expected MCV size, including all the pieces

+                       /* pased by reference, but fixed length (name, tid, ...) */


In src/include/statistics/statistics.h, there is some extraneous whitespace that needs
removing.


mark

Commits

  1. Convert pre-existing stats_ext tests to new style

  2. Add support for multivariate MCV lists

  3. Improve ANALYZE's strategy for finding MCVs.

  4. Clone extended stats in CREATE TABLE (LIKE INCLUDING ALL)

  5. Try again to fix accumulation of parallel worker instrumentation.

  6. Adjust psql \d query to avoid use of @> operator.

  7. Message style fixes

  8. Add security checks to selectivity estimation functions