VirtTipsAndTricksFedOptionClauseSupportHow to handle SPARQL-FED queries for SPARQL endpoints with no OPTION() clause supported? Suppose the following sample scenario: Assume the following SPARQL-FED query: PREFIX wp: <> PREFIX atlasterms: <> PREFIX efo: <> SELECT DISTINCT ?wpTitle ?dbXref ?expressionValue WHERE { { GRAPH <http://wikipathways> { ?pwElement dcterms:isPartOf ?wpPathway . ?wpPathway dc:identifier <> . ?wpPathway dc:title ?wpTitle . ?pwElement wp:bdbEnsembl ?dbXref . } SERVICE <> { ?value atlasterms:hasFactorValue ?factor . ?value atlasterms:isMeasurementOf ?probe . ?value atlasterms:pValue ?pvalue . ?value rdfs:label ?expressionValue . ?probe atlasterms:dbXref ?dbXref . ?disFactor rdfs:subClassOf+ efo:EFO_0000408 . ?disease rdf:type ?disFactor . ?disFactor rdfs:label ?label . } } } Execute the query from Virtuoso sparql endpoint As result you should get the following error: Virtuoso 37000 Error SP031: SPARQL compiler: SERVICE <> at line 18 does not support OPTION (...) clause for triples so SPARQL query can not be composed The error message means that the sparql endpoint does not support OPTION clause. Basically, one should be able to use the following command to interrogate a target SPARQL endpoint (if initial SPARQL-FED fails): SPARQL LOAD SERVICE <{SPARQL-END-POINT-URL}> DATA So in our example it would be: LOAD SERVICE <> DATA ; Related How to discover the capabilities of a SPARQL endpoint en route to enhancing SPARQL-FED usage from Virtuoso instances?