I can only answer for one advantage I specifically know of regarding graph DB's over key value: dynamic, mergeable schemas which enforce data integrity WITHIN

I can only answer for one advantage I specifically know of regarding graph DB's over key value: dynamic, mergeable schemas which enforce data integrity WITHIN the database rather than with code on top of it. There are many, many people on HN who are much more knowledgeable than I am on graph DB's, and I sure as hell hope they answer on this question. I'm curious if this supports the RDF, OWL, and SPARQL standards? I'm a little tired of graph DB's that focus on scale, rather than speed and flexibility though. A good one to check out is Stardog. http://stardog.com/ http://stardog.com/ I think it just went into 1.0.