Data Modeling and NoSQL

To the question “How relevant is data modeling in the world of NoSQL?” I give the following answer.

  The main purpose of data modeling is to understand the business, some application domain, some user world.  The model becomes a representation of that world -- the "things" in it, the relationships among those things and any constraints on those things or relationships.  A secondary purpose is to build a database to contain information which pertains to and describes that domain.  Hence, the business data model should not be concerned with issues of physical stored representation, or the transformations/manipulations/constraints which are imposed to facilitate implementation in some data (storage) management system.  That could be a relational DBMS, or a NoSQL tool.  Generally we speak of the model coming first, then the implementation, and finally, the data gets collected and stored according to the model.  However, increasingly the data already exists in some form.  Which leaves us with the task of figuring out what it means, what it represents -- that is, understanding the data as it represents some user domain.  NoSQL tools are often designed to deal with existing data and to process it more efficiently (that may be an oversimplification!).   Either way, you must understand the business in order to make sense of the data. 

BOTTOM LINE:  it is vitally important to understand the principles, methods, and approaches of data modeling which can help you get to an understanding of the data and the business domain it represents.  Whether using traditional database management tools or NoSQL tools you still need to understand the data.