Horton

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

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Andres Freund <andres@anarazel.de>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>, Mark Dilger <hornschnorter@gmail.com>, Adrien Nayrat <adrien.nayrat@dalibo.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-02T17:18:52Z
Lists: pgsql-hackers 
On 03/02/2018 04:29 AM, Andres Freund wrote:
> Hi,
> 
> On 2018-02-24 23:01:59 +0100, Tomas Vondra wrote:
>> Sadly, this patch series does not seem to move forward very much, and
>> I'm not sure how to change that :-/
> 
> What's your estimate about the patchset's maturity?
> 

It's dying of old age.

On a more serious note, I think the basics are pretty solid - both the
theory and the code (which mostly builds on what was introduced by the
CREATE STATISTICS thing in PG10).

I'm sure there are things to fix, but I don't expect radical reworks.
There are limitations I'd like to relax (say, allowing expressions
etc.), but those are clearly PG12 stuff at this point.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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