| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Danny Shemesh <dany74q(at)gmail(dot)com> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: Extended multivariate statistics are ignored (potentially related to high null fraction, not sure) |
| Date: | 2022-06-01 20:08:38 |
| Message-ID: | YpfHRiK02KvETKhj@momjian.us |
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| Thread: | |
| Lists: | 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(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com
Indecision is a decision. Inaction is an action. Mark Batterson
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