Improve join selectivity estimation using extended statistics

From: Konstantin Knizhnik <k(dot)knizhnik(at)postgrespro(dot)ru>
To: PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>
Cc: Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>
Subject: Improve join selectivity estimation using extended statistics
Date: 2021-01-27 16:51:32
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

Original thread is:

Following Yugo's advice, I have splitted this patch into two:
1. Extending auto_explain extension to generate extended statistics in
case of bad selectivity estimation.
2. Taken in account extended statistics when computing join selectivity.

Now this thread will contain only patches for join selectivity estimation.

> However,
> IIUC, the clausesel patch uses only functional dependencies statistics for
> improving join, so my question was about possibility to consider MCV in the
> clausesel patch.
Sorry, do not have idea right now how to use MCV for better estimation
of join selectivity.

Konstantin Knizhnik
Postgres Professional:
The Russian Postgres Company

Attachment Content-Type Size
extended_statistic_join_selectivity-1.patch text/x-patch 7.9 KB


Browse pgsql-hackers by date

  From Date Subject
Next Message Andres Freund 2021-01-27 17:09:58 Re: Printing backtrace of postgres processes
Previous Message Tomas Vondra 2021-01-27 16:41:36 Re: [PoC] Non-volatile WAL buffer