Horton

Re: Remove useless GROUP BY columns considering unique index

Andrei Lepikhov <lepihov@gmail.com>

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From: Andrei Lepikhov <lepihov@gmail.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Zhang Mingli <zmlpostgres@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, jian he <jian.universality@gmail.com>
Date: 2024-11-29T06:35:56Z
Lists: pgsql-hackers 
On 11/29/24 09:39, David Rowley wrote:
> On Fri, 29 Nov 2024 at 15:02, David Rowley <dgrowleyml@gmail.com> wrote:
>> I've attached an updated patch that gets rid of the
>> get_unique_not_null_attnos() function completely and uses the
>> RelOptInfo.indexlist and RelOptInfo.notnullattnums.
> 
> I forgot to do a local commit before sending v8. Fixed in the attached v9.
1. Thread reference in the patch comment doesn't work.
2. May it be possible to move remove_useless_groupby_columns in the 
second commit? It would be easier to review the differences.

-- 
regards, Andrei Lepikhov

Commits

  1. Detect redundant GROUP BY columns using UNIQUE indexes

  2. Defer remove_useless_groupby_columns() work until query_planner()