Re: Syntax vs Semantics vs XML Schema vs RDF Schema vs QNames vs URIs (was RE: Using urn:publicid: for namespaces)

[freed from spam trap -rrs]

 Message-ID: <3B80D131.4C8A680D@signal.qinetiq.com>
 Date: Mon, 20 Aug 2001 04:59:12 -0400 (EDT)
 From: David Allsopp <dallsopp@signal.qinetiq.com>
 CC: www-rdf-logic@w3.org, www-rdf-interest@w3.org
References: <2BF0AD29BC31FE46B78877321144043114B533@trebe003.NOE.Nokia.com>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Patrick.Stickler@nokia.com wrote:
> 
> > Indeed, if you think of a set of triples as being rows in a relational
> > database table, then ask what would be the primary key of
> > that table?  The
> > only sensible answer is that the primary key must be the
> > combination of the
> > subject and predicate.  The "semantics" could also be
> > considered to be a
> > kind of "business rule", to use an expression from a different domain.
> > Taking this relational database viewpoint, each node must
> > necessarily have a
> > value (or label), but it may be that a particular
> > implementation could hide
> > the label, or exclude it from serialization.
> 
> Exactly. This is what I was trying to get at with my examples that
> autogenerated identities of "anonymous" nodes based on their
> "context" made up of the subject and predicate. Having the same
> consistent identity makes comparison of values and enforcement
> of constraints much more straight forward.

As I said before; I like the idea, but I don't see how it can work in
practice, because we don't know the complete context (which may differ
from agent to agent, and from time to time) and an incomplete context
can be ambiguous.

Regards,

David.

-- 
/d{def}def/u{dup}d[0 -185 u 0 300 u]concat/q 5e-3 d/m{mul}d/z{A u m B u
m}d/r{rlineto}d/X -2 q 1{d/Y -2 q 2{d/A 0 d/B 0 d 64 -1 1{/f exch d/B
A/A z sub X add d B 2 m m Y add d z add 4 gt{exit}if/f 64 d}for f 64 div
setgray X Y moveto 0 q neg u 0 0 q u 0 r r r r fill/Y}for/X}for showpage

Received on Tuesday, 21 August 2001 08:05:03 UTC