Message-ID: <4CE19EF7.2090407@lelarge.info>
Date: Mon, 15 Nov 2010 21:58:31 +0100
From: Guillaume Lelarge <guillaume@lelarge.info>
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To: Chris Ruprecht <chris@ruprecht.org>
CC: pgsql-admin@postgresql.org
Subject: Re: Pre-Allocate tablespace on disk
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Le 15/11/2010 20:42, Chris Ruprecht a écrit :
> Hello,
> 
> I was wondering if there is a way to pre-allocate tablespace on disk before adding data and indexes.
> My understanding is:
> PG writes data into files sequentially. If more space is needed, disk space is requested from the OS and if there is space, the OS will give PG a file system block and PG will write data/indexes until that block is full and so on.
> Other database that I have worked with before and that I'm still working with, allow you to pre-allocate disk space so you get huge chunks of contiguous space at one, which has major impacts on database performance.
> 
> Can this be done with PG at all?

No. A tablespace is a directory on PostgreSQL. And you can't allocate
space for a directory.

> If not, is this planned for any time in the future?

AFAICT, nope.


-- 
Guillaume
 http://www.postgresql.fr
 http://dalibo.com