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Re: Re 2: [TF-ENT] Querying datasets with default plus named graphs

From: Axel Polleres <axel.polleres@deri.org>
Date: Tue, 13 Oct 2009 14:29:17 +0100
Cc: "Birte Glimm" <birte.glimm@comlab.ox.ac.uk>, "Ivan Herman" <ivan@w3.org>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
Message-Id: <D74F1FB6-BEAC-43F9-A49E-17291922464A@deri.org>
To: "Seaborne, Andy" <andy.seaborne@hp.com>

On 13 Oct 2009, at 08:50, Seaborne, Andy wrote:

>
>
> > -----Original Message-----
> > From: public-rdf-dawg-request@w3.org [mailto:public-rdf-dawg- 
> request@w3.org]
> > On Behalf Of Axel Polleres
> > Sent: 12 October 2009 23:45
> > To: Birte Glimm
> > Cc: Ivan Herman; SPARQL Working Group
> > Subject: Re: Re 2: [TF-ENT] Querying datasets with default plus  
> named graphs
> >
> > (catching up too slow recently ...  :-/)
> >
> > +1 to "identify the status as is (limited usefulness of named  
> graphs)
> > and pointers to solutions how this could be fixed (either as
> > concrete suggestions for extension marked at risk or just an
> > informative suggestion of future extensions)"
>
> -1: this text is judging the issue.

hmmm, I agree that  "(limited usefulness of named graphs)" is judging,  
indeed.
but we should note the issue (in a more neutral wording maybe), yes?

> It was not an objective of the TF to make datasets work with  
> entailment (for some definition of "work" that has not been  
> articulated).

we had already discussed CompositeDatasets (http://www.w3.org/2009/sparql/wiki/Feature:CompositeDatasets 
)
which were not among the favorite/chosen features.

>  Note: I want the mixed entailment case to work because that is  
> deployed practice.
>  Let's note that BGP RDFS-entailment currently requires all the  
> triples in the graph (it's most obvious given the informative RDFS  
> Entailment Rules in RDF-MT anyway).  It would be something else (and  
> useful) to have entailment work with a background vocabulary.  The  
> rules entailment regime will give us that, maybe others, so I don't  
> see there is a problem.

yup, it is complementary.

>
> A graph in a dataset can be the union of other graphs in the dataset  
> so having one graph as the union of vocabulary and data is already  
> possible and done in practice but it's just not the only way that  
> things can be setup.

that's what I tried to illustrate with the "implicit closure" approach  
mentioned in the last mail, yes.
which approach did you mean here with "possible and done in practice"?  
that one?

best,
Axel

>  It seems to me that we are trying to force one model of dataset for  
> one situation on all possible uses, entailment and non-entailment  
> related.


>
>         Andy
>
>
Received on Tuesday, 13 October 2009 13:29:52 GMT

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