We've been working to narrow this problem further, and came up with a far smaller example:
This query fails to produce the expected result: prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> prefix skos: <http://www.w3.org/2004/02/skos/core#> prefix owl: <http://www.w3.org/2002/07/owl#> SELECT * WHERE { <http://rabbit.computas.int:8180/sublima-webapp-1.0-SNAPSHOT/topic/topic000747> ?semrelation ?object . ?semrelation rdfs:subPropertyOf skos:semanticRelation ; a owl:ObjectProperty . ?object rdf:type skos:Concept . } However, if I remove a owl:ObjectProperty ., it works! Moreover: DESCRIBE <http://www.w3.org/2004/02/skos/core#broader> produces: @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix skos: <http://www.w3.org/2004/02/skos/core#> . @prefix owl: <http://www.w3.org/2002/07/owl#> . skos:broader rdf:type owl:ObjectProperty . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . skos:broader rdfs:label "Bredere"@no ; owl:inverseOf skos:narrower ; rdfs:subPropertyOf skos:semanticRelation . so, the owl:ObjectProperty is clearly there. The first query has results in this SQL: SELECT __id2i ( "s-1-1-t0"."P" ) AS "semrelation", __ro2sq ( "s-1-1-t0"."O" ) AS "object" FROM DB.DBA.RDF_QUAD AS "s-1-1-t0", DB.DBA.RDF_QUAD AS "s-1-1-t1", DB.DBA.RDF_QUAD AS "s-1-1-t2", DB.DBA.RDF_QUAD AS "s-1-1-t3" WHERE "s-1-1-t0"."S" = __i2idn ( __bft( 'http://rabbit.computas.int:8180/sublima-webapp-1.0-SNAPSHOT/topic/topic000747' , 1)) AND isiri_id ( "s-1-1-t0"."O") AND ( "s-1-1-t1"."S" < min_bnode_iri_id ()) AND "s-1-1-t1"."P" = __i2idn ( __bft( 'http://www.w3.org/2000/01/rdf-schema#subPropertyOf' , 1)) AND isiri_id ( "s-1-1-t1"."O") AND "s-1-1-t1"."O" = __i2idn ( __bft( 'http://www.w3.org/2004/02/skos/core#semanticRelation' , 1)) AND ( "s-1-1-t2"."S" < min_bnode_iri_id ()) AND "s-1-1-t2"."P" = __i2idn ( __bft( 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type' , 1)) AND isiri_id ( "s-1-1-t2"."O") AND "s-1-1-t2"."O" = __i2idn ( __bft( 'http://www.w3.org/2002/07/owl#ObjectProperty' , 1)) AND "s-1-1-t3"."P" = __i2idn ( __bft( 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type' , 1)) AND isiri_id ( "s-1-1-t3"."O") AND "s-1-1-t3"."O" = __i2idn ( __bft( 'http://www.w3.org/2004/02/skos/core#Concept' , 1)) AND "s-1-1-t0"."P" = "s-1-1-t1"."S" AND "s-1-1-t0"."P" = "s-1-1-t2"."S" AND "s-1-1-t1"."S" = "s-1-1-t2"."S" AND "s-1-1-t0"."O" = "s-1-1-t3"."S" OPTION (QUIETCAST) whereas if I remove the owl:ObjectProperty, I get SELECT __id2i ( "s-1-1-t0"."P" ) AS "semrelation", __ro2sq ( "s-1-1-t0"."O" ) AS "object" FROM DB.DBA.RDF_QUAD AS "s-1-1-t0", DB.DBA.RDF_QUAD AS "s-1-1-t1", DB.DBA.RDF_QUAD AS "s-1-1-t2" WHERE "s-1-1-t0"."S" = __i2idn ( __bft( 'http://rabbit.computas.int:8180/sublima-webapp-1.0-SNAPSHOT/topic/topic000747' , 1)) AND isiri_id ( "s-1-1-t0"."O") AND ( "s-1-1-t1"."S" < min_bnode_iri_id ()) AND "s-1-1-t1"."P" = __i2idn ( __bft( 'http://www.w3.org/2000/01/rdf-schema#subPropertyOf' , 1)) AND isiri_id ( "s-1-1-t1"."O") AND "s-1-1-t1"."O" = __i2idn ( __bft( 'http://www.w3.org/2004/02/skos/core#semanticRelation' , 1)) AND "s-1-1-t2"."P" = __i2idn ( __bft( 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type' , 1)) AND isiri_id ( "s-1-1-t2"."O") AND "s-1-1-t2"."O" = __i2idn ( __bft( 'http://www.w3.org/2004/02/skos/core#Concept' , 1)) AND "s-1-1-t0"."P" = "s-1-1-t1"."S" AND "s-1-1-t0"."O" = "s-1-1-t2"."S" OPTION (QUIETCAST) Sorry I haven't got a public endpoint with exactly these data, we might put that up, but for now, I don't think I actually need the objectproperty restriction, so I'll just drop it in my app. Kind regards Kjetil Kjernsmo -- Senior Knowledge Engineer Mobile: +47 986 48 234 Email: kjetil.kjern...@computas.com Web: http://www.computas.com/ | SHARE YOUR KNOWLEDGE | Computas AS PO Box 482, N-1327 Lysaker | Phone:+47 6783 1000 | Fax:+47 6783 1001
