From hb at stat.berkeley.edu  Thu Feb 14 16:54:38 2008
From: hb at stat.berkeley.edu (Henrik Bengtsson)
Date: Thu, 14 Feb 2008 07:54:38 -0800
Subject: [Rd] Vector binding on harddisk
In-Reply-To: <47B45CDC.2060803@vanderbilt.edu>
References: <47B426BE.9010606@gmx.net> <47B45ABD.4010304@bank-banque-canada.ca>
	<47B45CDC.2060803@vanderbilt.edu>
Message-ID: <59d7961d0802140754x216c9753la5ebcfa415439a39@mail.gmail.com>

On Thu, Feb 14, 2008 at 7:23 AM, Jeffrey Horner
<jeff.horner at vanderbilt.edu> wrote:
> Paul Gilbert wrote on 02/14/2008 09:14 AM:
>
> >
>  > _ wrote:
>  >> Hi all,
>  >> Using big vectors (more than 4GB) is unfortunately not possible under
>  >> Windows or other OS's if not enough RAM exists.
>  >
>  > This is NOT true. It is not limited by RAM, but rather by RAM and swap
>  > space.  With 500G hard disks at about $100, the more serious limitation
>  > is a 32bit OS.  Speed is a different consideration, but I doubt that
>  > taking over what the OS is suppose to do will be the real answer.
>
>  Umm... swap... yeah... My experience with any code that I write that
>  needs to use swap is to reboot the machine and rewrite my code NOT to
>  use swap.

...and the OS can never predict how you are going to access the data -
as a developer you will always be able to write a much faster
file-based "database" compared with a generic swap that you have
little control over.

/Henrik

>
>  Jeff
>
>
>  >
>  > Paul
>  >
>  >> Could it be possible to implement an a new data type in R, like a
>  >> vector, but instead holding the information in memory, the data lies on
>  >> an file. If data is accessed, the data type vector get the information
>  >> automatically from the file.
>  >> There is a package out there (named ff) but the accessed boundary have
>  >> to be declared by the user this is a disadvantage.
>  >>
>  >> Greetings.
>  >>
>  >> ______________________________________________
>  >> R-devel at r-project.org mailing list
>  >> https://stat.ethz.ch/mailman/listinfo/r-devel
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>  >
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>
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[Rd] Vector binding on harddisk
Henrik Bengtsson