Re: X.500 as document repository

yeongw@spartacus.psi.com Tue, 25 February 1992 15:05 UTC

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To: Sylvain Langlois <sylvain@cli53an.edf.fr>
Subject: Re: X.500 as document repository
Cc: lazear@gateway.mitre.org, osi-ds@cs.ucl.ac.uk, mcguthry@gateway.mitre.org
Reply-To: yeongw@psi.com
In-Reply-To: Your message of Mon, 24 Feb 92 17:49:00 +0000. <8195.698953740@cli53an>
Date: Tue, 25 Feb 1992 08:27:07 -0500
From: yeongw@spartacus.psi.com

> Using  the  X.500 technology  to store  "pointers"  to
> documents  is fine,  using  it as a   "file transfer tool"  is totally
> inadequate.
> The technology should provide "hints" to another application suited to
> this kind of job (e.g. FTP or FTAM or Z39.50). You cannot retrieve the
> file system of a host you lookup through the DNS!

I mostly agree with this.

In fact, I would go even further and say that, except in limited
cases, X.500 isn't even so great at storing pointers to individual
documents. The problem is that X.500 has this hierarchical view
of the world, which doesn't necessarily map well into the world
of documents (in general repositories of information). It also
isn't so hot as far as searching capabilities go ...

In my view, the problem of retrieving information can be divided
into three stages:

	1. identifying candidate repositories for the
	   information (documents)

	2. searching repositories to identify individual
	   items of information (documents) that would
	   be of interest

	3. delivering the information (documents) to the
	   end user.

I believe X.500 is the perfect technology for 1., and has some
limited use for 2. It is completely inadequate for 3.  The
justification for my position is somewhat long, so I won't
go over it here, and create yet another overly long message :-).

If you care to find out how I justify my position, please ftp
the document wp/ps/nir.ps from ftp.psi.com. It's a technical report
I wrote on this subject.


Wengyik