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

help / color / mirror / Atom feed
From: Manfred Spraul <manfred@colorfullife.com>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: pgsql-hackers@postgresql.org
Subject: Re: Database Kernels and O_DIRECT
Date: Thu, 16 Oct 2003 07:51:49 +0200
Message-ID: <3F8E31F5.9020703@colorfullife.com> (raw)
In-Reply-To: <3F8DB5D7.1060600@dunslane.net>
References: <BBB237C0.5B35%jamesr@best.com>
	<15890.1066232585@sss.pgh.pa.us>
	<3F8DB5D7.1060600@dunslane.net>

Andrew Dunstan wrote:

>
> I have wondered (somewhat fruitlessly) for several years about the 
> possibilities of special purpose lightweight file systems that could 
> relax some of the assumptions and checks used in general purpose file 
> systems. Such a thing might provide most of the benefits of a 
> "database kernel" without imposing anything extra on the database 
> application layer.

CPU is usually cheap compared to disk io.

There are two things that might be worth looking into:
Oracle released their cluster filesystem (ocfs) as a GPL driver for 
Linux. It might be interesting to check how it performs if used for 
postgres, but I fear that it implicitely assumes that the bulk of the 
caching is performed by the database in user space.
And using O_DIRECT for the WAL logs - the logs are never read.

--
    Manfred





view thread (13+ messages)  latest in thread

Message-ID: <3F8E31F5.9020703@colorfullife.com>
Permalink:  ../3F8E31F5.9020703@colorfullife.com/
Also on:    postgresql.org/message-id/3F8E31F5.9020703@colorfullife.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-hackers@postgresql.org
  Cc: manfred@colorfullife.com, andrew@dunslane.net
  Subject: Re: Database Kernels and O_DIRECT
  In-Reply-To: <3F8E31F5.9020703@colorfullife.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