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SPARQL Dataset Graph Pattern

From: Olivier Corby <Olivier.Corby@sophia.inria.fr>
Date: Thu, 23 Feb 2006 17:02:59 +0100
Message-ID: <43FDDCB3.2030803@sophia.inria.fr>
To: public-rdf-dawg-comments@w3.org

I think there is something wrong in the first definition of section 8 
Querying the Dataset. I mentionned it last year and it was nicely 
corrected by Andy but the correction disappeared (may be there is a good 
reason, but I ignore it) :


Definition:  RDF Dataset Graph Pattern

If D is a dataset {G, (<u1>, G1), ...}, and P is a graph pattern then S 
is a pattern solution of RDF Dataset Graph Pattern GRAPH(g, P) if either of:

    1. g is an IRI where g = <ui> for some i, and S is pattern solution 
of P on target graph Gi.
    2. g is a variable, S maps the variable g to <ui> and S is a pattern 
solution of P on target graph Gi


Should be :


    1. g is an IRI where g = <ui> for some i, and S is pattern solution 
of P on dataset {Gi, (<u1> G1), ...}
    2. g is a variable, S maps the variable g to <ui> and S is a pattern 
solution of P on dataset {Gi, (<u1> G1), ...}



The reason is that pattern P may contain another dataset graph pattern 
that must be matched on the dataset, not on Gi only, e.g. :

graph ?src1  { PATTERN  .  graph ?src2  { PATTERN } }


Best regards,

Olivier.
Received on Thursday, 23 February 2006 16:03:35 GMT

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