As we discussed in the introduction to the chapter, there are a variety of data stores that are providing alternatives to traditional databases. The term Big Data has become popular in the last few years. While there is no agreed definition of Big Data, there are a few shared characteristics:

• Unstructured Data: There is no specific structure to the data
• Large Volumes: Typically, more volumes than that can be processed by traditional databases, for example, log streams, Facebook posts, tweets
• Easily Scalable: Typically provides options to scale horizontally and vertically

Hadoop, Cassandra, and MongoDB are among the popular options.

In this section, we will take MongoDB as an example to connect using Spring Data.