- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Thu, 14 Jan 2010 16:03:23 +0100
- To: Toby Inkster <tai@g5n.co.uk>
- Cc: Chris Welty <cawelty@gmail.com>, semantic-web <semantic-web@w3.org>
- Message-ID: <9d93ef961001140703r273c87ffn97c959d4c439e528@mail.gmail.com>
Hi all Agreed with many points said - Don't fix what is not broken - Get rid or let die obscure constructions such as bags and reification - Simplify, simplify, simplify :) But please don't kill blank nodes ! My use case (not academic, used on a daily basis) is translation from a model to another using SPARQL CONSTRUCT. Such translations (but it is yet another story to be discussed in another thread) are a very powerful way to pass from a model to another, without mapping declarations or commitments from either side. Exemple Graph 1 is a document data base using foaf:Document class with Dublin Core attributes such as dcterms:creator and dcterms:subject Graph 2 is a data base of expertises using a ex:Expertise class with object properties ex:expert, ex:topic and ex:supportDocument I can construct instances of ex:Expertise in G2 out of instances of foaf:Document in G1, but I have no URI in G1 for those. So I need bnodes in my query, such as : CONSTRUCT { _:x a ex:Expertise. _:x ex:expert ?p. _:x ex:topic ?t. _:x ex:supportDoc ?d} WHERE { ?d a foaf:Document. ?d dcterms:creator ?p. ?d dcterms:subject ?t } Unless SPARQL provide ways to generate URIs on the fly for my ex:Expertise instances. But I don't think it does. Seems very specific, but think about it before killing bnodes. Or provide something similar w/o them. Bernard 2010/1/14 Toby Inkster <tai@g5n.co.uk> > On Wed, 2010-01-13 at 11:00 -0500, Chris Welty wrote: > > I suppose we don't really need to discuss whether we should > > investigate an "RDF 2.0", but rather what kinds of requirements > > various RDF users have that they would like to be considered (I'd like > > this thread to be less "+1" and "-1" messages, and more "I'd like to > > see RDF support x...") > > Adopt SPARQL's data model for all future Semantic Web standards -- for > all SW protocols and serialisations. > > The major differences between SPARQL's data model and RDF are: > > * Explicit support for named graphs > * Literal subjects > * Blank node predicates > > (Though it might be a good idea to phase out blank nodes.) > > -- > Toby A Inkster > <mailto:mail@tobyinkster.co.uk> > <http://tobyinkster.co.uk> > > > -- Bernard Vatant Senior Consultant Vocabulary & Data Engineering Tel: +33 (0) 971 488 459 Mail: bernard.vatant@mondeca.com ---------------------------------------------------- Mondeca 3, cité Nollez 75018 Paris France Web: http://www.mondeca.com Blog: http://mondeca.wordpress.com ----------------------------------------------------
Received on Thursday, 14 January 2010 15:03:57 UTC