Tuplestores are one of the most common backend formats for storing graphs — you only need triples, or quads if you want timestamps. Everything's stored as (Enti

Tuplestores are one of the most common backend formats for storing graphs — you only need triples, or quads if you want timestamps. Everything's stored as (Entity, Attribute, Value) in the same table, with all of the Es and As being references, and with the Vs as references when the tuple is a graph edge but as atoms when it's a graph node. Pretty much every existing RDF database is a tuplestore underneath, or abuses a relational database as a crappy tuplestore that won't get you fired for installing it.