pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  

help / color / mirror / Atom feed
From: Peter Geoghegan <pg@bowt.ie>
To: Юрий Соколов <funny.falcon@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Sokolov Yura <funny.falcon@postgrespro.ru>
Cc: Claudio Freire <klaussfreire@gmail.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: PostgreSQL-Dev <pgsql-hackers@postgresql.org>
Subject: Re: Small improvement to compactify_tuples
Date: Sat, 4 Nov 2017 16:35:59 -0700
Message-ID: <20171104233559.GA8580@marmot> (raw)
In-Reply-To: <CAL-rCA10_Tf47iCPMLrR9DVKS0cG-we4eRU-7bxtgCPeAbrqog@mail.gmail.com>
References: <20170515171331.taa44gjbc7p3aaul@alvherre.pgsql>
	<468f371fe05c1de09c4dc101435ef93d@postgrespro.ru>
	<9c4bc2ff302be669717101bc33127fd0@postgrespro.ru>
	<a9327865736cd63820f009141917063f@postgrespro.ru>
	<CAGTBQpbrCqPLTfM10TPb3G+DXwDzv=5zQzhuDs9RJV1LUK0+WA@mail.gmail.com>
	<6873f723fd9cfed7389a2f461016e167@postgrespro.ru>
	<21392.1509677196@sss.pgh.pa.us>
	<CAL-rCA10_Tf47iCPMLrR9DVKS0cG-we4eRU-7bxtgCPeAbrqog@mail.gmail.com>
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-hackers>

Юрий Соколов <funny.falcon@gmail.com> wrote:
>tps is also reflects changes:
>~17ktps with qsort
>~19ktps with bucket sort
>
>Also vacuum of benchmark's table is also improved:
>~3s with qsort,
>~2.4s with bucket sort

One thing that you have to be careful with when it comes to our qsort
with partially presored inputs is what I like to call "banana skin
effects":

https://postgr.es/m/CAH2-WzkU2xK2dpZ7N8-A1MvuUTTUvhqkfnA+eUtwNwCtgyCJgw@mail.gmail.com

This may have nothing at all to do with your results; I'm just pointing
it out as a possibility.

-- 
Peter Geoghegan


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers



view thread (60+ messages)  latest in thread

Message-ID: <20171104233559.GA8580@marmot>
Permalink:  ../20171104233559.GA8580@marmot/
Also on:    postgresql.org/message-id/20171104233559.GA8580@marmot

 · 

reply
Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-hackers@postgresql.org
  Cc: pg@bowt.ie, funny.falcon@gmail.com, tgl@sss.pgh.pa.us, funny.falcon@postgrespro.ru, klaussfreire@gmail.com, alvherre@2ndquadrant.com, hlinnaka@iki.fi
  Subject: Re: Small improvement to compactify_tuples
  In-Reply-To: <20171104233559.GA8580@marmot>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox