In this chapter, we have gone through a bit of history starting from the 1970s. We were in total control of the data models that were rather stable and the applications that were pretty simple. The relational databases were a perfect fit in the old days. With the emergence of object-oriented programming and the explosion of the web applications on the pervasive Internet, the nature of the data has been extended from structured to semi-structured and unstructured. Also, the application has become more complex. The relational databases could not be perfect again. The concept of Big Data was created to describe such challenges and NoSQL databases provide an alternative resolution to the relational databases.

NoSQL databases are of a wide variety. They provide some common benefits and can be classified by the NoSQL database type. Apache Cassandra is one of the NoSQL databases that is a blend of Google BigTable and Amazon Dynamo. The elegance of its architecture inherits from the DNA of these two parents.

In the next chapter, we will look at the flexible data model supported by Cassandra.