Re: ERROR: corrupt MVNDistinct entry

Andrei Lepikhov <lepihov@gmail.com>

From: Andrei Lepikhov <lepihov@gmail.com>
To: Richard Guo <guofenglinux@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-12-25T02:33:57Z
Lists: pgsql-hackers
On 12/24/24 15:00, Richard Guo wrote:
> Any thoughts?
I have a couple of notes.
1. The nulling_relids provides us sensible information about possible 
nulls inside the input. We are not using it to estimate the number of 
such nulls for now. Does Your idea consist of obtaining 'clear' 
statistics and reusing nulling_relids knowledge somewhere later?
2. It is ok for Vars. But what about expressions? We use equal() in 
distinct, MCV and dependencies modules. Do we need to remove nulls 
before using extended statistics as a general rule?

-- 
regards, Andrei Lepikhov



Commits

  1. Ignore nullingrels when looking up statistics

  2. Make Vars be outer-join-aware.