@freakazoid I'd be fine with a graph database, as long as it has sufficient performance on relational tasks (comparable to something like PostgreSQL), and offers a similar set of guarantees - thinking of things like referential integrity and 'proper' transactions.

Do either of those meet those goals? The performance doesn't need to be exactly like PostgreSQL (as that has been seeing optimization for a long time) but also not so slow that it's only really useful in an academic setting :p