Possibly answered sufficiently by [Virtuoso SQL query of a SPARQL query in iSQL](https://stackoverflow.com/questions/40370880/virtuoso-sql-query-of-a-sparql-query-in-isql)?
– TallTedJul 18 '17 at 20:23
1
[Jena ARQ](https://jena.apache.org/documentation/query/explain.html), [Blazegraph](https://wiki.blazegraph.com/wiki/index.php/Explain), [GraphDB](http://graphdb.ontotext.com/documentation/standard/explain-plan.html)
– Stanislav KralinJul 18 '17 at 20:39
I read your question to say that Virtuoso was the target SPARQL endpoint, but maybe not? If Virtuoso is indeed the target, have you read the Q&A to which I linked? Or the documentation to which it links?
– TallTedJul 19 '17 at 23:35