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Re: Demo SPARQL notes

From: <samwald@gmx.at>
Date: Tue, 17 Apr 2007 20:28:13 +0200
Cc: public-semweb-lifesci@w3.org
Message-ID: <20070417182813.181350@gmx.net>
To: Bijan Parsia <bparsia@cs.man.ac.uk>

> >the OWL property restrictions produce RDF  
> > graphs that are quite convoluted and hard to query.
> 
> I'm not sure exactly what you mean here. Hmm. Do you mean that the  
> OWL in RDF/XML syntax is rather convoluted? 

No I meant the RDF triple structure, independent of any syntax. 


> Are you querying for classes or for instances?

Classes.


> Do you mean "How on earth could any end user specify this?" 

No no, in this case I was mainly thinking about the developers. Of course we can fix anything (e.g. overly complicated RDF graphs because of OWL restrictions) through adding new features (e.g. using reasoners instead of Sparql queries, adding a macro function to Sparql engines), but I would rather prefer simple and elegant solutions. One of my main attractions of RDF to me was the fundamental simplicity of its approach, and this simplicity would get lost by taking this path. Of course, this is just personal preference.

> Would you need it to be added? In Pellet, for example, you can ask  
> for the superclasses of an arbitrary class expression without adding  
> it to the ontology.

I have to confess that I was not aware that Pellet offers that feature. How would you judge the scalability of this approach with the upcoming version of Pellet, e.g. for an ontology containing around 200.000 triples, would it be possible to run a webserver that uses this approach to answer concurrent queries of dozens of users without excessive lag?


> Sorry for any misunderstandings I may have had and then generated :)

Oh, your mail was very helpful. Thanks!

-- Matthias






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Received on Tuesday, 17 April 2007 18:28:15 GMT

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