There is no reason why a single data management system cannot be built that can do everything that either a file system or a database can do (I have been building one).

It is an object store called Didgets (i.e. Data Widgets). Each Didget has a specific type. One type is used to hold unstructured data like a file does. These Didgets are unsurprisingly called File Didgets. Other types of Didgets can hold lists (used to create hierarchical folders, music play lists, photo albums, etc.).

Others hold sets of Key/Value pairs which are used to create a tagging system for other Didgets or columns in a relational table.

Using a variety of Didgets, I have been able to create hierarchical file systems where a simple query can find one or thousands of files instantly out of 200 million+ based on the values of any tags attached.

In the same container (called a pod), it can store tens of thousands of relational tables; each one capable of having 100,000+ columns and billions of rows.

The system is 'multi-model' so it could manage hierarchical data, relational data, graph data, or anything managed by a NoSQL system.

It is not only versatile, but is incredibly fast.