Tinkerpop SPARQL-Gremlin plugin not using Janusgraph indices

[thevalzo]

I have loaded into Janusgraph an RDF dataset, creating a node for each entity having "uri" property over which has been defined a Janusgraph index. However, when I write a query like :
g.sparql("" "SELECT? x WHERE {? x v: uri" http://dbpedia.org/resource/Barack_Obama ".}." "")
i receive the following message: "WARN org.janusgraph.graphdb.transaction.StandardJanusGraphTx
    - Query requires iterating over all vertices [()]. For better performance, use indexes ".
This is strange even because in the Gremlinator paper the benchmark is done with use of indexes. How can i make the indexes be used in the query?

[harsh9t]

You will probably have to explicitly create indexes in JanusGraph before executing the queries. You could do this via the tool itself or by a groovy script. In the Gremlinator paper, explicit indexes were created for all graph dbs that were included in the experiments.

[thevalzo]

I have create a composite index, in fact as you can see below the gremlin query give back the result immediately, instead the sparql query doesn't find the index (in this example I use the force-index option). Is it possible that I have this issue because I use sparql-gremlin 3.4.0 with janusgraph 0.3.1 (probably containing tinkerpop 3.3.3)?