- From: Antoine Zimmermann <antoine.zimmermann@insa-lyon.fr>
- Date: Thu, 03 Mar 2011 15:18:00 +0100
- To: Richard Cyganiak <richard@cyganiak.de>
- CC: Reto Bachmann-Gmür <reto.bachmann@trialox.org>, Jiří Procházka <ojirio@gmail.com>, Pat Hayes <phayes@ihmc.us>, William Waites <ww@styx.org>, nathan@webr3.org, Ivan Shmakov <oneingray@gmail.com>, semantic-web@w3.org
Le 02/03/2011 20:35, Richard Cyganiak a écrit : > Reto, > > On 2 Mar 2011, at 18:50, Reto Bachmann-Gmür wrote: >>> Is there any practical difference between bnodes and normal nodes, >>> except the scope (and necessity) of their name? >> >> Yes, a graph with bnodes can potentially be simplified: the same meaning may be expressed with a more lean graph, i.e. with less nodes and triples. If all your nodes are uris you cannot do simplifications with rdf entaillment. > > Reality check please! > > When was the last time you saw such a non-lean RDF graph in the wild, outside of examples and test cases? Can you name a production system that routinely performs the simplification you talk about, with user benefit? > > The question was about practice. You describe a thought experiment. I think it's a good example of a complication in RDF that was added for sound theoretical reasons, but has failed to deliver any value whatsoever in practice. Being lean is an abstract property. It cannot fail nor succeed. With that said, I agree that Reto's answer is not very "practical". Anyway, even if there is no practical difference between bnodes and normal nodes except the scope, there is a /significant/ practical difference between bnodes and normal nodes, namely, the scope. Bnodes are needed (and cannot be avoided?) in the presence of rdf:List, owl:Restriction, owl:propertyChain, owl:unionOf, owl:intersectionOf, and so on. Cheers, -- Antoine Zimmermann Researcher at: Laboratoire d'InfoRmatique en Image et Systèmes d'information Database Group 7 Avenue Jean Capelle 69621 Villeurbanne Cedex France Lecturer at: Institut National des Sciences Appliquées de Lyon 20 Avenue Albert Einstein 69621 Villeurbanne Cedex France antoine.zimmermann@insa-lyon.fr http://zimmer.aprilfoolsreview.com/
Received on Thursday, 3 March 2011 14:18:41 UTC