query-9169f5dfce9f4b1baedffaef60a2c331

rq turtle/ttl

Federates searches with https://query.wikidata.org/bigdata/namespace/categories/sparql?query=SPARQL example, but that turned out to be a fail. this> somewhat after https://query.wikidata.org/bigdata/namespace/categories/sparql?query=SPARQL - which I vaguely understand to be a SPARQL endpoint. Can we access that endpoint thru WDQS using a federated query? If so, the SPARQL below is a candidate; I tried replacing gas:service with <https://query.wikidata.org/bigdata/namespace/categories/sparql?query=SPARQL, but find it's not accessible via WDQS, but available from Wikidata Query Service/CategoriesI came across

Use at

• https://query.wikidata.org/sparql

PREFIX gas: <http://www.bigdata.com/rdf/gas#>
prefix mediawiki: <https://www.mediawiki.org/ontology#> 

SELECT * WHERE {
SERVICE gas:service {
     gas:program gas:gasClass "com.bigdata.rdf.graph.analytics.BFS" .
     gas:program gas:linkType mediawiki:isInCategory .
     gas:program gas:traversalDirection "Reverse" .
     gas:program gas:in <https://en.wikipedia.org/wiki/Category:Ducks>. # one or more times, specifies the initial frontier.
     gas:program gas:out ?out . # exactly once - will be bound to the visited vertices.
     gas:program gas:out1 ?depth . # exactly once - will be bound to the depth of the visited vertices.
     gas:program gas:maxIterations 8 . # optional limit on breadth first expansion.
  }
} ORDER BY ASC(?depth)

Query found at

• https://www.wikidata.org/wiki/Wikidata:Request_a_query/Archive/2018/12