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Re: Using RDB for a large OWL-DL database.

From: Enrico Franconi <franconi@inf.unibz.it>
Date: Thu, 28 Sep 2006 17:50:28 +0200
Message-Id: <8474E7FE-2605-4CEC-9A66-C90A224EE897@inf.unibz.it>
Cc: Bijan Parsia <bparsia@isr.umd.edu>, public-owl-dev@w3.org
To: Sören Auer <auer@informatik.uni-leipzig.de>

Do you have a soundness and correctness proof of you reduction?
It would be interesting to see.

On 28 Sep 2006, at 16:58, Sören Auer wrote:

> Bijan Parsia wrote:
>> Just out of curiosity, what fragment of OWL does your translation  
>> handle? I believe LUMB turns out to be in hornSHIQ:
> Good question. I'm not able to say that in two words.
> The algorithm first makes some subsumption inferences (currently on  
> the basis of explicit subClassOf, oneOf, intersectionOf and unionOf  
> axioms/descriptions).
> Classification is done with regard to almost all OWL axioms and  
> descriptions, by generating a DB view for each description/axiom on  
> a triple table and combining these views as needed. In case of  
> mutual recursion, there is currently some approximation used for  
> computation of an initial class extend, which is refined by a  
> second run. We didn't use some fix point algorithm due to  
> performance reasons and for many practical scenarios this doesn't  
> seem to be needed.
> Non-unique names assumption turns out to be problematic, OWLDB does  
> not check if certain individuals are the same. But I guess that  
> won't be very problematic, when an individual is listed twice (for  
> classes/properties of course it's a bigger deal).
> I think it's a bit hard to compare the OWLDB approach to classic DL  
> reasoners, since only subsumption and classification are supported,  
> both with a different set of (in some cases only partially)  
> supported OWL descriptions/axioms.
> Let me know if you want to have a glance at the paper I'm currently  
> writing once I have a first draft (might take 2-3 more weeks).
> Cheers,
> Sören
Received on Thursday, 28 September 2006 15:51:00 UTC

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