- From: Carlos Buil Aranda <cbuil@fi.upm.es>
- Date: Tue, 3 Jul 2012 12:57:08 -0400
- To: "Polleres, Axel" <axel.polleres@siemens.com>
- Cc: "andy.seaborne@epimorphics.com" <andy.seaborne@epimorphics.com>, "greg@evilfunhouse.com" <greg@evilfunhouse.com>, "public-rdf-dawg@w3.org" <public-rdf-dawg@w3.org>
- Message-ID: <CABdcz9GO5iA-=kOyaz=4DJZq_zv-DGKspZ+F0Jkof_c03HeUPA@mail.gmail.com>
yes, it would be only an editorial change, just modify at the beginning of Section 2 sonething like this: The SERVICE keyword instructs a federated query processor to invoke a portion of a SPARQL query against a remote SPARQL endpoint that complies with the SPARQL Protocol [SPROT] 2012/7/3 Polleres, Axel <axel.polleres@siemens.com> > In what form would tyou want to reference reference to the SPARQL protocol? > If it's only an editorial change that clarifies matter, that should be ok, > IMO. > > Axel > > > -- > Dr. Axel Polleres > Siemens AG Österreich > Corporate Technology Central Eastern Europe Research & Technologies > CT T CEE > > Tel.: +43 (0) 51707-36983 > Mobile: +43 (0) 664 88550859 > Fax: +43 (0) 51707-56682 mailto:axel.polleres@siemens.com > > > > ________________________________ > > From: Carlos Buil Aranda [mailto:cbuil@fi.upm.es] > Sent: Tuesday, 3 July 2012 4:48 PM > To: Andy Seaborne; Gregory Williams > Cc: public-rdf-dawg@w3.org > Subject: Re: draft response for PW1 > > > Dear all, > > I updated the response to PW. However and looking at the document, > I think that it is a bit underspecify and it should be added a reference to > the SPARQL protocol next to the explanation of what the SERVICE keyword > does. Would it be possible to add it informally? > > Carlos > > > 2012/6/29 Andy Seaborne <andy.seaborne@epimorphics.com> > > > I wonder if there is a need to specify the dataset. The > point about SERVICE is to send the query to another place, presumably > because it has the data and the sender, and their service engine, does not. > This is emphasising the general SPARQL service that reads graphs off the > web and queries them. > > Dataset description is used to select graphs from a local > pool. The use of GRAPH maybe enough to allow the sender to select the > graphs of interest. The only case missing is a merge of graphs to be the > default graph. > > If an application wants to access a general purpose SPARQL > processor, then it uses the the SPARQL protocol - not as part of a query > because , after all, SERVICE happens inside a local query execution. > Shipping off a subpart of the query from one SPARQL engine to another > seems a minor use case and if we were addressing that, there is a lot of > other machinery that we'd want to put in place. > > Andy > > > On 28/06/12 22:11, Gregory Williams wrote: > > > > On Jun 28, 2012, at 4:43 PM, Carlos Buil Aranda > wrote: > > > > Dear all, > > I attach the draft response for PW-1 > http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2012Jun/0007.html< > http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2012Jun/0007.html > > > > draft: > http://www.w3.org/2009/sparql/wiki/CommentResponse:PW1 < > http://www.w3.org/2009/sparql/wiki/CommentResponse:PW1> > > > > Hi Carlos, > > You say: "in the SPARQL 1.1 grammar there is no > way for specifying the default dataset to query." > > Am I simply misunderstanding what you're saying? > For query, you specify it with FROM/FROM NAMED. > > You continue: > > """ > In the same way there is no mechanism for > specifying named graphs since the SERVICE keyword only provides mechanisms > for directing specific pieces of SPARQL queries to an SPARQL endpoint. > Thus, you correctly understood the specification. > """ > > I've brought this up before, but why can't the > dataset for a SERVICE be specified using protocol parameters? i.e.: > > SERVICE < > http://example.com/sparql?default-graph-uri=XXX&named-graph-uri=YYY < > http://example.com/sparql?default-graph-uri=XXX&named-graph-uri=YYY> > { > ... } > > Shouldn't this just work? (Assuming implementors > have done the legwork to choose between using '?query=' and '&query=' when > constructing the service invocation URI.) > > > """ > The other possibility you point out (to send the > default and named datasets defined by the main query) is not allowed: the > SERVICE keyword translates the pattern inside into a new query to the > remote dataset, using a SELECT * WHERE {...} without specifying the > original query datasets. However, inside the SERVICE clause you can use a > subquery in which you can specify to which graph direct the query: > > PREFIX foaf: <http://xmlns.com/foaf/0.1/> > SELECT ?name > WHERE { > SERVICE <http://example.org/sparql> { > SELECT * WHERE > { > GRAPH <http://example.org/graph> > { ?person foaf:name ?name ; foaf:mbox ?mbox } > } > } > } > """ > > That won't specify the dataset, though. It only > specifies the active graph for matching the two triple patterns. Is that > what you are intending to point out? > > .greg > > > > > > > >
Received on Tuesday, 3 July 2012 16:58:00 UTC