Comment by ghc

> the relational model can subsume "graph" queries, but for all the reasons Codd laid out back in the 60s... network (aka connected graph) databases cannot do the latter.

Except network databases have little in common with graph databases...they're much more closely related to hierarchical databases.

I would say that Graph databases are now a strict superset of relational databases, not the other way around. In a graph database a node's named edge can naturally point to a node of any type or having any property schema. Doing this in a relational model requires one of several approaches that could only be classified as fighting against the model (or torturing it, as my PI liked to say).