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Re: URN Resolution Paths Considered Harmful

From: Fisher Mark <FisherM@is3.indy.tce.com>
Date: Mon, 10 Jul 95 11:06:00 PDT
To: "'URI'" <uri@bunyip.com>
Message-Id: <30016ADC@MSMAIL.INDY.TCE.COM>

(Apologies for the late reply, as unfortunately URI group activies cannot be 
at the top of my priority list...)

To reiterate, I think that we can learn from what database software vendors 
had to suffer through during the 1980s.  Pre-relational databases (esp. 
hierarchial and network CODASYL) forced programmers to specify up-front how 
a particular "name" could be resolved.  Much time was spent where I worked 
(a non-relational DB company) on developing a tool that allowed you to query 
the database arbitrarily, as customers needed to make queries ("resolve 
names") in manners not allowed by the hard-coded index paths.  The big 
reason that relational databases have supplanted CODASYL databases is that 
the process of determining access paths ("resolution paths") is off-loaded 
to the computer.  That increase in flexibility has changed the creation of 
small DB programs from a painful task to relatively trivial task, as well as 
enabling the production in finite time of large DB program suites 
manipulating hundreds of tables.  This advance in database technology is 
comparable to the advance in programming capability provided by 
compiled/interpreted languages vs. assembly language.

>From my point of view, the URN resolution services are just a database 
system where the columns to search on are the naming authority (SchemeID in 
"Generic URN Syntax") and the document name (ElementID in "Generic URN 
Syntax").  Even the advent of database replication services has not, to my 
eyes, sparked any revival in the idea of encoding the query path 
("resolution path") into the query; it seems as if this is all supported by 
behind-the-scenes machinery (database views, table name synonyms, and such).

1) URN resolution services are just a database system; and
2) The most successful database technology so far (relational databases) 
does not include the resolution path in the query, but leaves up to the 
I think that we should follow the direction of other database systems by not 
encoding the resolution path into the URN.
Mark Fisher                            Thomson Consumer Electronics
fisherm@indy.tce.com                   Indianapolis, IN
Received on Monday, 10 July 1995 12:01:19 UTC

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