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

help / color / mirror / Atom feed
From: Josh Berkus <josh@agliodbs.com>
To: Andres Freund <andres@2ndquadrant.com>
Cc: Jeff Janes <jeff.janes@gmail.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Planner performance extremely affected by an hanging transaction (20-30 times)?
Date: Fri, 27 Sep 2013 13:57:02 -0700
Message-ID: <5245F11E.20804@agliodbs.com> (raw)
In-Reply-To: <WM!93b9a5691f0628ebed5547d1ebe916326a0f388cbdc28742bef1b0c7862375a07b801f17c707cbdf6a3104b7920696af!@asav-1.01.com>
References: <CAC6=Lj7fYUWzcKLU6X7-8D1q+ijvBrGmwS2dw4mixhH8F8KSAw@mail.gmail.com>
	<CAMkU=1wjnoFOrzVqLpUg2Ja=+kd_sv2HP4+cF-Y7r4a3uHT-tg@mail.gmail.com>
	<1379944816.30390.YahooMailNeo@web162903.mail.bf1.yahoo.com>
	<5815.1380018947@sss.pgh.pa.us>
	<e8795f5e292a0bd1a4d8ebbcb54e4a98.squirrel@shrek.krogh.cc>
	<WM!41fcd3fa079d542735fe69d3254859689c1085f7c897fa6e9a9b828ad9d2c80ba7b6b2c4c67c942a6115262993147370!@asav-1.01.com>
	<5241CF2A.2070309@agliodbs.com>
	<CAMkU=1ys-fB2Nczt=LT1pVHzK3Jv4Jb-67N29Gzyx3nraweoZQ@mail.gmail.com>
	<20130925175312.GB5578@awork2.anarazel.de>
	<CAMkU=1yy-YEQVvqj2xJitT1EFkyuFk7uTV_hrOMGyGMxpU=N+Q@mail.gmail.com>
	<20130925184330.GC5578@awork2.anarazel.de>
	<WM!93b9a5691f0628ebed5547d1ebe916326a0f388cbdc28742bef1b0c7862375a07b801f17c707cbdf6a3104b7920696af!@asav-1.01.com>
List-Unsubscribe:  <mailto:majordomo@postgresql.org?body=unsub%20pgsql-performance>

Andres, Jeff,


>> As far as I can tell, the only downside of doing that is that, since hint
>> bits might be set later, it is possible some dirty pages will get written
>> unhinted and then re-dirtied by the hint bit setting, when more aggressive
>> setting would have only one combined dirty write instead.  But that seems
>> rather hypothetical, and if it really is a problem we should probably
>> tackle it directly rather than by barring other optimizations.
> 
> I am - as evidenced - too tired to think about this properly, but I
> think you might be right here.

Any thoughts on a fix for this we could get into 9.2.5?

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com


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



view thread (25+ messages)  latest in thread

Message-ID: <5245F11E.20804@agliodbs.com>
Permalink:  ../5245F11E.20804@agliodbs.com/
Also on:    postgresql.org/message-id/5245F11E.20804@agliodbs.com

 · 

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-performance@postgresql.org
  Cc: josh@agliodbs.com, andres@2ndquadrant.com, jeff.janes@gmail.com
  Subject: Re: Planner performance extremely affected by an hanging transaction (20-30 times)?
  In-Reply-To: <5245F11E.20804@agliodbs.com>

* 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