Re: Removing useless DISTINCT clauses

From: David Rowley <david(dot)rowley(at)2ndquadrant(dot)com>
To: "Finnerty, Jim" <jfinnert(at)amazon(dot)com>
Cc: Stephen Frost <sfrost(at)snowman(dot)net>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Removing useless DISTINCT clauses
Date: 2018-08-27 05:24:06
Message-ID: CAKJS1f9GxhaP_6pa=DsNEbXw1dJVPQ7scZ9qhg7+P2w4yXSpHg@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On 25 August 2018 at 04:05, Finnerty, Jim <jfinnert(at)amazon(dot)com> wrote:
> I'll explore a proper way to test that it's in the single-relation case, and will post a separate thread for the 'remove unnecessary DISTINCT' optimization.

See: has_multiple_baserels() in allpaths.c

--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Michael Paquier 2018-08-27 05:29:06 Re: [HACKERS] Proposal to add work_mem option to postgres_fdw module
Previous Message Thomas Munro 2018-08-27 04:12:20 Re: simplehash.h comment