That is orthogonal, NoSQL can be used as a relational DB too. SQL is one way to do a relational DB. Also what I describe is close to SQL if e.g. you declare a

That is orthogonal, NoSQL can be used as a relational DB too. SQL is one way to do a relational DB. Also what I describe is close to SQL if e.g. you declare a set of properties and property types for each "filetype". Relational is one aspect of a DB. Schemaless or not is another aspect.