Re: Extended multivariate statistics are ignored (potentially related to high null fraction, not sure)

Поиск
Список
Период
Сортировка
От Bruce Momjian
Тема Re: Extended multivariate statistics are ignored (potentially related to high null fraction, not sure)
Дата
Msg-id YpfHRiK02KvETKhj@momjian.us
обсуждение исходный текст
Ответ на Extended multivariate statistics are ignored (potentially related to high null fraction, not sure)  (Danny Shemesh <dany74q@gmail.com>)
Ответы Re: Extended multivariate statistics are ignored (potentially related to high null fraction, not sure)  (Danny Shemesh <dany74q@gmail.com>)
Список pgsql-general
On Wed, Jun  1, 2022 at 07:28:58PM +0300, Danny Shemesh wrote:
> Hey everyone,
> 
> I'm working on improving gathered statistics on several large tables (2TB /
> 500M records);
> I've created extended stats on correlated columns, ran analyze, compared the
> pre and post explains, and it seems as though the extended statistics are
> ignored - 
> the estimation doesn't change much, and I can accurately derive the est. rows
> from multiplying the single-column freqs from pg_stats with the supplied
> values.
> 
> 
> Context:
> - pg 12.8

You should be on the most recent version of 12.X, and I do see some
extended statistics change in the later releases you are missing.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Indecision is a decision.  Inaction is an action.  Mark Batterson




В списке pgsql-general по дате отправления:

Предыдущее
От: Danny Shemesh
Дата:
Сообщение: Extended multivariate statistics are ignored (potentially related to high null fraction, not sure)
Следующее
От: David Rowley
Дата:
Сообщение: Re: unoptimized nested loops