Re: Default Graph Contents

>
> Please see my answers inline. -- Souri.


Thank you for your response.

My position is that R2RML should not say anything about it. This will be
> decided by semantics of SPARQL (protocol and query language). In the
> scenario you mentioned, current SPARQL semantics says that the query will be
> executed against the default graph, which in a simple case consists of the
> set of triples in the unnamed graph.


My reading of the SPARQL spec is that it does not define the contents of the
default graph: from http://www.w3.org/TR/sparql11-query/#rdfDataset

"The definition of RDF Dataset does not restrict the relationships of named
and default graphs. Information can be repeated in different graphs;
relationships between graphs can be exposed."

So my thought is that if R2RML is silent on the topic, and since the SPARQL
spec doesn't prescribe an answer, then R2RML implementors are free to
determine what is in the "default", default graph.

-David

Received on Wednesday, 9 March 2011 19:03:51 UTC