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Re: [TF-ENT] Querying datasets with default plus named graphs

From: Ivan Herman <ivan@w3.org>
Date: Thu, 08 Oct 2009 06:24:21 +0200
Message-ID: <4ACD6975.8000803@w3.org>
To: Axel Polleres <axel.polleres@deri.org>
CC: "Seaborne, Andy" <andy.seaborne@hp.com>, Birte Glimm <birte.glimm@comlab.ox.ac.uk>, SPARQL Working Group <public-rdf-dawg@w3.org>


Axel Polleres wrote:
[skip]
>>
>>> I guess
>>> this default graph would be temporary, right and if I query again
>>> without the from clause, I would again get no results, right?
>>>
>>> Ok, assuming I understand that right, I would much prefer to keep
>>> entailments local to the graph.
>>
>> +1
>

Same here, +1

> +1 to keep entailments local to the separate  graphs in the DS
> (<chairhatoff> although  I  personally consider it a drawback that you 
> can't refer to ontologies from named graphs)
>

Hm. Yes, this seems to be a consequence which is a bit disagreeable 
indeed:-(

In OWL, I can of course use owl:import in my WHERE clause (Birte, this 
is all right, isn't it?) which is not that bad, the user has to make 
things explicit. But this does not help the RDFS case.

It also raises an issue on the RIF side. RIF rules cannot be expressed 
in RDF. How would one add RIF rules to an entailement regime if we 
wanted to cover RIF? It might be a showstopper for that case:-(

Ivan


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Received on Thursday, 8 October 2009 04:21:12 GMT

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