- From: Graham Klyne <Graham.Klyne@Baltimore.com>
- Date: Sat, 16 Jun 2001 21:13:48 +0100
- To: Sergey Melnik <melnik@db.stanford.edu>
- Cc: w3c-rdfcore-wg@w3.org
Sergey,
I vaguely remember this being raised, and must say I have deep reservations
about that approach.
Right now I cannot say exactly why I think this is a problem, and I won't
fight the case here, other than to note that I might object later if/when I
can crystalize my concerns.
(Part of my objection is that any mechanism that is based on merely
statistical uniqueness (i.e. digest-based) has no place in the core of the
RDF framework. In an appendix to RFC 2938, I have calculated some
probabilities of collision using MD5; the numbers of digest values in use
does not need to be astronomically large (c. 10^18 or so) before the
probability of collision becomes quite significant. Applications may
choose to take such statistical chances, but I don't think a fundamental
technology framework like RDF should do so.)
#g
--
At 06:58 PM 6/15/01 -0700, Sergey Melnik wrote:
> > do you really mean this last claim?
> > I suspect you meant that all parsers should assign a predictable genid
> > given a common RDF/XML description mentioning a resource. 'all parsers
> > should assign the same genid to the same resource' would be magic, since
> > many times parsers won't have that information accessible.
>
>Dan,
>
>just to provide a pointer, a whole while ago I proposed an algorithm for
>doing exacty that "magic". A summary of the proposal can be found at
>http://nestroy.wi-inf.uni-essen.de/rdf/sum_rdf_api/ under "URI
>generation for anonymous resources" (by Peter Hannappel and Reinhold
>Klapsing). I believe, if needed, this algorithm can be tweaked to
>eliminated the problems wrt using XOR (as pointed out by Brian long
>ago).
------------------------------------------------------------
Graham Klyne Baltimore Technologies
Strategic Research Content Security Group
<Graham.Klyne@Baltimore.com> <http://www.mimesweeper.com>
<http://www.baltimore.com>
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Received on Saturday, 16 June 2001 16:20:19 UTC