Subject: Re: Adding and filling new column on big table
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Jonathan Blitz <jb@anykey.co.il>
Cc: 'Francisco Reyes' <lists@stringsutils.com>,
	pgsql-performance@postgresql.org
In-Reply-To: <012501c6842c$bb8438f0$ddf71005@jonathanlaptop>
References: <012501c6842c$bb8438f0$ddf71005@jonathanlaptop>
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Date: Tue, 30 May 2006 15:07:15 -0500

On Tue, 2006-05-30 at 16:04, Jonathan Blitz wrote:
> > 
> > Most laptop drives are only 5,400 RPM which would make a transaction like
> > you are describing likely take a while.
> 
> Not sure what my one is but it is new(ish).
> 
> > 
> > No desktop at home you could try it on?
> > I think the problem with the laptop is likely it's drive.
> 
> I suppose I could do but I need to install PostgreSQL there and then copy
> over the database.

Keep in mind, most, if not all IDE drives lie about fsync, so the speed
of the drive is a limit only if you're actually writing a lot of data. 
If you're doing a lot of little transactions, the drive should be lying
and holding the data in cache on board, so the speed should be OK.