Introduction to NoSQL databases

We already know basic features and characteristics of the traditional Relational Database Management Systems (RDBMSs), which we presented in Chapter 5, R with Relational Database Management Systems (RDBMSs). We are also well aware of their limitations and specific requirements, for example, that they contain predefined schema, are vertically scalable which results in constant hardware upgrades to catch up with data growth, and they generally do not support unstructured or hierarchical data.

Non-relational or NoSQL databases attempt to fill these gaps and some of them are specialized in certain aspects more than others. In the next section, we will briefly present several NoSQL databases and their particular use cases.

Review of leading non-relational databases

To say that NoSQL databases are what SQL databases are not, may be a bit of an over-simplification. However, this statement is true to some extent and the following characteristics can shed some light on...