Currently the triple pattern matching in the SPARQL engine has to check that every Triple returned by calls to GetTriplesWithXY() on a ISparqlDataset actually returns the correct triples using equality checks because with some of our in-memory indexes they aren't guaranteed to return exactly the triples asked for due to the way we currently handle collisions.
If CORE-247 gets completed then we can remove this requirement since it will guarantee that our index structures always return only the things they are asked for