From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
---|---|
To: | Peter Geoghegan <pg(at)bowt(dot)ie> |
Cc: | Heikki Linnakangas <hlinnaka(at)iki(dot)fi>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Polyphase merge is obsolete |
Date: | 2017-08-30 19:48:09 |
Message-ID: | CA+TgmoYnY+37WhX0y6SBxe3WTBx1tBLM_0nuYuRn260z73ePRQ@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Wed, Aug 30, 2017 at 2:54 PM, Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> I noticed that this is in the upcoming CF 1 for v11. I'm signed up to review.
>
> I'd like to point out that replacement selection is also obsolete,
> which is something I brought up recently [1]. I don't actually have
> any feature-driven reason to want to kill replacement selection - it's
> just an annoyance at this point. I do think that RS is more deserving
> of being killed than Polyphase merge, because it actually costs users
> something to continue to support it. The replacement_sort_tuples GUC
> particularly deserves to be removed.
>
> It would be nice if killing RS was put in scope here. I'd appreciate
> it, at least, since it would simplify the heap routines noticeably.
> The original analysis that led to adding replacement_sort_tuples was
> based on certain performance characteristics of merging that have
> since changed by quite a bit, due to our work for v10.
These are separate topics. They should each be discussed on their own
thread. Please don't hijack this thread to talk about something else.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2017-08-30 19:51:39 | Re: The case for removing replacement selection sort |
Previous Message | Robert Haas | 2017-08-30 19:45:16 | Re: expanding inheritance in partition bound order |