Get distinct graphs runs out of memory

[ktk]

While many statistical queries are really fast in QLever, selecting distinct graphs does not seem to be one of them at the moment. The official SPARQL spec would require

SELECT DISTINCT ?g WHERE {
  GRAPH ?g { ?s ?p ?o}
} 

which runs out of memory pretty much immediately.

Stardog also allows this short form, which I like:

SELECT * WHERE {
  GRAPH ?g {}
} 

[ktk]

Turns out the short hand is actually in SPARQL: w3c/sparql-dev#205 (comment)