Date: Tue, 23 Aug 1994 09:04:57 -0400
Message-Id: <199408231304.JAA65161@inca.gate.net>
To: uri@bunyip.com
From: hoymand@gate.net (Dirk Herr-Hoyman)
Subject: Z39.50 and URI
I would like to bring to the attension of this group the work being done on
Z39.50, and search and retrieval protocol, and how is might relate to URI.
The latest specification for Z39.50-1994 (also known as V3) is available in
<ftp://ftp.loc.gov/z3950>. There is also a mail list discussion on Z39.50
and URLs, zurl-l@vinca.cnidr.org (subscribe to listserv@vinca.cnidr.org).
There are 2 aspects of Z39.50 which I would like to touch on here. To
really understand this, you will need to look at the V3 spec (and I warn
you, its about 175 pages).
1) Connectionless vs. connection-oriented. The work so far in URI has a
connectionless orientation. Z39.50, on the other hand, is connection
oriented. It is meant to be run in a session, with results from a request
being used later. This doesn't map very well to a URL, and is a large
reason why there is no Z39.50 URL yet.
It occurs to me that this has broader architectural implications for URI.
Are we going to work within this connectionless paradigm only? We have
been able to shoehorn FTP into a URL, but this is tame compared to what
happens in Z39.50.
2) URC and Variant sets. Z39.50 was developed by the library community.
While not the only use for Z39.50 by any means, most databases at this
point are library catalogs. Clearly this contains the type of information
that we are proposing would go into a URC. One aspect of this is the
Variant set. While syntactically (and protocol wise) different, I think
the goal is the same, to provide information on choices for retrieval.
Are there two sets of railroad tracks being built on this mountain? Will
they fit together when they meet?
-- Dirk Herr-Hoyman <hoymand@gate.net> | Practice CyberBeach Publishing | random acts of kindness * Internet publishing services | and senseless beauty Lake Worth, Florida, USA | Home Page: <URL:http://www.gate.net/~hoymand/cyberbeach.html> Phone: +1.407.540.8309