Introduction to NoSQL

In the past couple of years, web application development usually required the usage of a relational database to store persistent data. Most developers are already pretty comfortable with using one of the many SQL solutions. So, the approach of storing a normalized data model using a mature relational database became the standard. Object-relational mappers started to crop up, giving developers proper solutions to marshal their data between the different parts of their application. But as the Web grew larger, more scaling problems were presented to a larger base of developers. To solve this problem, the community created a variety of key-value storage solutions that were designed for better availability, simple querying, and horizontal scaling. This new kind of data store became more and more robust, offering many of the features of the relational databases. During this evolution, different storage design patterns emerged, including key-value storage, column storage,...