Unfortunately based on a wrong hypothesis:
However most of the NoSQL tools seem to be NoRelational. As I see it, many of these tools map closely to the model that the relational model replaced.. the hierarchical model. Some describe themselves as hierarchical.
While not sure what NoSQL databases the author is referring, from my point of view the common denominator of column stores, document databases and key-value stores is the key-value model which is not hierarchical. On the other hand, graph databases are using the graph model at their core which is again different from the hierarchical model. The Java Content Repository implementations (e.g. Jackrabbit) are the only systems I’m aware of being hierarchical, so the hypothesis doesn’t apply.
NoSQL Databases Aren’t Hierarchical originally posted on the NoSQL blog: myNoSQL