Re: Using multiple extended statistics for estimates

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

From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Mark Dilger <hornschnorter@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-12-05T17:51:45Z
Lists: pgsql-hackers

Attachments

On Thu, Dec 05, 2019 at 06:15:54PM +0100, Tomas Vondra wrote:
>On Sun, Dec 01, 2019 at 08:08:58PM +0100, Tomas Vondra wrote:
>>On Sat, Nov 30, 2019 at 03:01:31PM -0800, Mark Dilger wrote:
>>>
>>>Are you planning to submit a revised patch for this?
>>>
>>
>>Yes, I'll submit a rebased version of this patch shortly. I got broken
>>because of the recent fix in choose_best_statistics, shouldn't take long
>>to update the patch. I do have a couple more related patches in the
>>queue, so I want to submit them all at once.
>>
>
>OK, here we go - these two patched allow applying multiple extended
>statistics, both for MCV and functional dependencies. Functional
>dependencies are simply merged and then applied at once (so withouth
>choose_best_statistics), statistics are considered in greedy manner by
>calling choose_best_statistics in a loop.
>

OK, this time with the patches actually attached ;-)


regards

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

Commits

  1. Apply multiple multivariate MCV lists when possible

  2. Apply all available functional dependencies