I am preparing for an upgrade to Virtuoso 6.1.2, and during testing I see that two almost identical queries give very different response time - the one with an extra restriction takes a lot longer(!) to complete.
At <URL: http://msoneutv.computas.no:8890/sparql >, copy&pasting the following query gives an almost immediate response: ============================== prefix sub: <http://xmlns.computas.com/sublima#> prefix rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> prefix rdfs:<http://www.w3.org/2000/01/rdf-schema#> prefix owl:<http://www.w3.org/2002/07/owl#> prefix xsd:<http://www.w3.org/2001/XMLSchema#> prefix yago:<http://dbpedia.org/class/yago/> prefix dct:<http://purl.org/dc/terms/> prefix foaf:<http://xmlns.com/foaf/0.1/> prefix cc:<http://creativecommons.org/ns#> prefix mo:<http://purl.org/ontology/mo/> prefix mm:<http://musicbrainz.org/mm/mm-2.1#> prefix mediasone:<http://www.computas.com/mediasone#> prefix mv:<http://www.computas.com/mediasone-vokabular/> prefix mi:<http://www.computas.com/mediasone-instanser/> DESCRIBE ?resource FROM <http://msone.computas.no/graphs/instance/nfi> FROM <http://msone.computas.no/graphs/help/mediasone> FROM <http://msone.computas.no/graphs/instance/mo> FROM <http://msone.computas.no/graphs/inferred/nfi/agent-realisation1> FROM <http://msone.computas.no/graphs/inferred/nfi/realisation1> FROM <http://msone.computas.no/graphs/inferred/mo/agent-realisation1> FROM <http://msone.computas.no/graphs/inferred/mo/realisation1> FROM <http://msone.computas.no/graphs/index/vocab_mediasone> FROM <http://msone.computas.no/graphs/index/mo_agent-classification> FROM <http://msone.computas.no/graphs/index/inferred_classification> FROM <http://msone.computas.no/graphs/index/nfi_agent-classification> FROM <http://msone.computas.no/graphs/index/instance_nfi> FROM <http://msone.computas.no/graphs/index/instance_mo> FROM <http://msone.computas.no/graphs/index/ontology_mediasone> WHERE { ?resource sub:literals ?title. ?title bif:contains "'her*'" . ?resource a <http://creativecommons.org/ns#Work> . ?resource dct:title ?actualtitle } ORDER BY ?actualtitle LIMIT 120 OFFSET 0 ============================== However, adding an extra restriction on ?resource, "?resource a <http://www.computas.com/mediasone-ontologi#Aktoer>", gives a very slow response ============================== prefix sub: <http://xmlns.computas.com/sublima#> prefix rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> prefix rdfs:<http://www.w3.org/2000/01/rdf-schema#> prefix owl:<http://www.w3.org/2002/07/owl#> prefix xsd:<http://www.w3.org/2001/XMLSchema#> prefix yago:<http://dbpedia.org/class/yago/> prefix dct:<http://purl.org/dc/terms/> prefix foaf:<http://xmlns.com/foaf/0.1/> prefix cc:<http://creativecommons.org/ns#> prefix mo:<http://purl.org/ontology/mo/> prefix mm:<http://musicbrainz.org/mm/mm-2.1#> prefix mediasone:<http://www.computas.com/mediasone#> prefix mv:<http://www.computas.com/mediasone-vokabular/> prefix mi:<http://www.computas.com/mediasone-instanser/> DESCRIBE ?resource FROM <http://msone.computas.no/graphs/instance/nfi> FROM <http://msone.computas.no/graphs/help/mediasone> FROM <http://msone.computas.no/graphs/instance/mo> FROM <http://msone.computas.no/graphs/inferred/nfi/agent-realisation1> FROM <http://msone.computas.no/graphs/inferred/nfi/realisation1> FROM <http://msone.computas.no/graphs/inferred/mo/agent-realisation1> FROM <http://msone.computas.no/graphs/inferred/mo/realisation1> FROM <http://msone.computas.no/graphs/index/vocab_mediasone> FROM <http://msone.computas.no/graphs/index/mo_agent-classification> FROM <http://msone.computas.no/graphs/index/inferred_classification> FROM <http://msone.computas.no/graphs/index/nfi_agent-classification> FROM <http://msone.computas.no/graphs/index/instance_nfi> FROM <http://msone.computas.no/graphs/index/instance_mo> FROM <http://msone.computas.no/graphs/index/ontology_mediasone> WHERE { ?resource a <http://www.computas.com/mediasone-ontologi#Aktoer> . ?resource sub:literals ?title. ?title bif:contains "'her*'" . ?resource a <http://creativecommons.org/ns#Work> . ?resource dct:title ?actualtitle } ORDER BY ?actualtitle LIMIT 120 OFFSET 0 ============================== Can any of you see an error in the query, any hints on where to log or debug, or anything else that can resolve this issue and make it possible to upgrade the production environment? (The queries are generated by a multimedia application, but its sourcecode can be changed if needed) -- Frode Roxrud Gill
