- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Sat, 5 Jun 2010 04:53:43 -0400
- To: Olaf Hartig <hartig@informatik.hu-berlin.de>
- Cc: public-rdf-dawg-comments@w3.org
* Olaf Hartig <hartig@informatik.hu-berlin.de> [2010-06-04 14:37+0200]
> Hello,
>
> The example in Section 2.1 of the Federation Extensions document [1] uses the
> void vocabulary wrongly. The default graph in this example contains RDF
> triples such as
>
> <http://GABABR1.example/SPARQL> a void:Dataset ;
> dcterms:subject entrez:h2550 .
>
> The variable ?service of the example query is then mapped to URI
> <http://GABABR1.example/SPARQL> and this URI is then used to identify a
> SPARQL service. That's not the meaning of void:Dataset. void:Dataset refers
> to a linked dataset and not to a SPARQL endpoint that exposes a linked
> dataset.
> I propose to adjust the example as follows:
>
> 1.) replace the abovementioned triples by the following (similar for the other
> SPARQL services):
>
> <http://GABABR1.example/dataset> a void:Dataset ;
> dcterms:subject entrez:h2550 ;
> void:sparqEndpoint <http://GABABR1.example/SPARQL> .
>
> 2.) replace the first triple patterns in the sample query by the following:
>
> # Find the service with the expertise.
> ?dataset dcterms:subject ?gene ;
> void:sparqEndpoint ?service .
> FILTER (?gene = entrez:h2550 || ?gene = entrez:h9568)
DONE V1.11
Does
<x> dcterms:subject <p> ; void:sparqEndpoint <s> .
imply that the the query should look for a named graph à la
SELECT ?y WHERE { GRAPH <x> { ?s <p> ?y } }
?
> BTW, the FILTER clause in the current example lacks a closing bracket.
DONE V1.11
> Greetings,
> Olaf
>
> [1] http://www.w3.org/TR/2010/WD-sparql11-federated-query-20100601/
V1.11 of http://www.w3.org/2009/sparql/docs/fed/service#varService
should address this fixes. tx kindly!
--
-ericP
Received on Saturday, 5 June 2010 08:54:20 UTC