Linking Wikidata to the Semantic Web
Wikidata is the linked database of Wikipedia and its sister projects from the Wikimedia foundation. Wikidata can be queried by SPARQL queries. Either through the WikiData Query Service (WDQS: http://query.wikidata.org) or its SPARQL endpoint at: https://query.wikidata.org/bigdata/namespace/wdq/sparql.
Both the WDQS and the SPARQL endpoint
do not allow submitting federated SPARQL queries. In our efforts to make Wikidata the central hub of linked data in the life science, being able to submit federated queries can be an asset.
Although federation is not supported from Wikidata, the SPARQL endpoint is accessible for other SPARQL endpoint that do support federation. We compare four federated SPARQL query
patterns to query Wikidata in combination with other semantic web formats.