I ran into some strange results from the DBPedia SPARQL endpoint and was
directed here. This query:
SELECT * WHERE { ?s a ?o }
when run against the default dataset[1] returns several results that only have
one variable binding (for ?o), instead of the expected two. In the results I'm
seeing, two erroneous results appear directly after one with ?s=<
http://nasa.dataincubator.org/spacecraft/1968-089A.json>. Both of these
erroneous results have ?o=foaf:Document. Is this a known problem? Might I
expect this problem to be fixed in the DBPedia endpoint anytime soon?
I also just noticed that (again on the default dataset) the of this query
DESCRIBE <http://www.cs.umd.edu/~hendler/>
doesn't include the single RDF triple in which that URI appears as the subject
(rdf:type foaf:Document). Obviously this is more of an expectations issue than
an actual error, but it struck me as odd. Is this the expected behavior of
DESCRIBE in Virtuoso? Is the algorithm used for DESCRIBE described anywhere?
thanks,
gregory williams
[1]
http://dbpedia.org/sparql?default-graph-uri=&query=select+*+where+%7B+%3Fs+a+%3Fo+%7D
