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FW: Model question

From: Kevin Thomas <KThomas@Ovid.com>
Date: Mon, 4 Aug 2003 08:27:46 -0600
Message-ID: <555F2B7B278B5348A28F665E6B0E43A4012F04E3@exchange-slc.ut.ovid.com>
To: www-zig@w3.org

Hello Kevin!

It turns out that my subscription mysteriously disappeared, so I don't think
this got through before.


-----Original Message-----
From: Kevin Thomas 
Sent: Thursday, July 24, 2003 11:08 PM
To: 'Kevin Gamiel'; www-zig@w3.org
Subject: RE: Model question

Hello Kevin!

Perhaps my perspective is a bit limited, but I think the answer is really
very simple.

1.  Databases are things that enclose the result of intellectual work.  They
are branded.  Entities who make databases, be they for-profit or
not-for-profit or individuals, like to have their work acknowledged, in at
least the minimal sense that the user knows "I'm searching BIOSIS" or "I'm
searching MedLine" or "I'm searching my buddy JoAnne's database".

2.  It has always been well-understood that the operation of searching is
not closed (in the sense that the operation of addition over integers is
closed, but the operation of division over integers is not closed).

3.  Several important things about a database don't have natural analogs for
subsets of documents that are in the database. That is, one important
characteristic of a database is the set of records contained therein, but
there are other important characteristics too.  Examples include the
last-update date, "about this database" links, the list of available MeSH
subheadings, pricing, and so forth.  As another writer noted, another thing
stored in a database is the set of indexes, as opposed to the set of

4.  Allowing for backreferences wasn't a clever hack -- it was driven by
market needs.  Back-referencing had been in A&I databases for about 20 or so
years before z39.50 version 2.  Librarians, who provided much of the major
initial push behind vendor adoption of z39.50, have always been clear that
backreferencing is a researcher's friend.  This is partly because of economy
of expression, and partly because they want to minimize user delay (and
system resource consumption) that would be caused by repeatedly running
lengthy sub-searches.

5.  Using a backreference doesn't turn a result set into a database, because
using a backreference doesn't add indexes, last-update date, pricing, or any
other database-level data.  Instead, using a backreference specifies
set-theoretic actions with the referred-to document set versus the set of
all documents in the database.

Just one man's opinion,

> -----Original Message-----
> From: Kevin Gamiel [mailto:kgamiel@cnidr.org] 
> Sent: Thursday, July 24, 2003 9:23 AM
> To: www-zig@w3.org
> Subject: Model question
> Hi folks,
> A discussion has come up on our GridIR list (http://www.gridir.org) 
> about models.  To aid that discussion, I have a question about the 
> Z39.50 model.
> The search service provides a method for applying a query expression 
> "directly" against a set of databases (DB), generating a logical, 
> server-side result set (RS).  The present service provides a 
> method for 
> retrieval of records from a RS.  The RS is *not* modelled 
> directly as a 
> DB, that is, the search service may not use an RS directly as 
> if it were 
> a DB.  However, type-1 and type-101 queries (at least), allow one to 
> include an RS reference as an operand, *effectively* turning 
> an RS into 
> a DB, though with some (minor?) loss of functionality.
> Was including an RS as a query operand a clever afterthought to avoid 
> changing the underlying data model, or is there a more significant 
> reason to maintain the DB/RS model distinction?
> Thanks!
> Kevin
> -- 
> Kevin Gamiel <kgamiel@cnidr.org>
> MCNC Center for Networked Information Discovery and Retrieval (CNIDR)
> http://www.mcnc.org
> http://www.cnidr.org

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Received on Monday, 4 August 2003 10:27:27 UTC

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