Another quick question to better understand Stardog technically. Some vendors claim their graph database are good for OLTP or for OLAP (and a new acronym is born: GOLAP, Graph-based Online Analytical Processing).
I'm not sure that OLTP or OLAP are helpful distinctions in this case. You could make the argument that it's a bit of both. Stardog supports transaction processing and between the use of machine learning, QB4ST, and the Cube Vocabulary, and virtual graphs you could argue that it's doing OLAP as well.
It probably depends on what you mean by realtime queries. Stardog doesn't do streaming queries like CSPARQL or some other streaming engine although it does evaluate them in a streaming fashion if possible. Perhaps that's what you might mean by near-realtime queries.
That's my understanding of it. It would be interesting to see other opinions on the subject. Hope that helps.