Re: Faster distinct query? - Mailing list pgsql-general

From David Rowley
Subject Re: Faster distinct query?
Date
Msg-id CAApHDvrecZLXdWNE00cb1bDAWO7jFDjJDoAToDAOZfMUyEuH5A@mail.gmail.com
Whole thread Raw
In response to Re: Faster distinct query?  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-general
On Thu, 23 Sept 2021 at 13:28, David G. Johnston
<david.g.johnston@gmail.com> wrote:
> Agreed, though if the query author needs to do that here we’ve violated the spirit of the declarative SQL language.
Atfirst blush nothing about the original query seems like it should be preventing parallelism.  Each worker builds its
owndistinct array then the final concatenation is made distinct. 

We don't parallelise DISTINCT / ORDER BY aggregates.

David



pgsql-general by date:

Previous
From: "David G. Johnston"
Date:
Subject: Re: Faster distinct query?
Next
From: David Rowley
Date:
Subject: Re: Faster distinct query?