- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Fri, 30 Sep 2011 11:28:43 +0200
- To: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>
- Cc: RDF Working Group WG <public-rdf-wg@w3.org>, public-rdf-dawg-comments@w3.org
Hi pa, (cc SPARQL comments list) On 29 Sep 2011, at 16:57, Pierre-Antoine Champin wrote: > I realize that a statement that I made: > > On 09/29/2011 04:42 PM, Pierre-Antoine Champin wrote: >> I know that SPARQL does not require that the default graph is *also* >> present as a named graph (though it does not forbid it) > > could be argued against by the way SPARQL defines a dataset: > >> An RDF Dataset comprises one graph, the default graph, which does not >> have a name, and zero or more named graphs, where each named graph is >> identified by an IRI. You are right. If taken literally, this definition [1] implies that an RDF Dataset can't have the same triples in the default graph and in a named graph. This clearly isn't the intention, so the wording is a bug in the SPARQL spec and needs to be fixed. The formal definition [2] is fine. (RDF graphs are set of triples. If two graphs contain the same triples, they are the same graph – they have no identity beyond the triples they contain.) Best, Richard [1] http://www.w3.org/TR/sparql11-query/#rdfDataset [2] http://www.w3.org/TR/sparql11-query/#sparqlDataset
Received on Friday, 30 September 2011 09:29:30 UTC