Abstract
The chapter presents how relational databases answer to typical NoSQL features, and, vice versa, how NoSQL databases answer to typical relational features. Open issues related to the integration of relational and NoSQL databases, as well as next database generation features are discussed. The big relational database vendors have continuously worked to incorporate NoSQL features into their databases, as well as NoSQL vendors are trying to make their products more like relational databases. The convergence of these two groups of databases has been a driving force in the evolution of database market, in establishing a new level of focus to resolving big data requirements, and in enabling users to fully use data potential, wherever data is stored, in relational or NoSQL databases. In turn, the database of choice in the future will likely be one that provides the best of both worlds: flexible data model, high availability, and enterprise reliability.
TopNosql Vs. Relational Databases
The comparison between relational and NoSQL databases can be discussed concerning different features such as work with different data formats, use of data schema, joins, consistency, scalability, high availability, and so on. But, considering the process of convergence of these two groups of databases, questions related to the point of comparison can be issued. However, the differences between these two groups of databases still exist, although they are not so clear as they were 10 years ago. Here, two approaches are used to explain the differences and similarities between relational and NoSQL databases:
Table 1 presents the typical NoSQL features (described in detail in Chapter 2) and how the three biggest vendors of relational databases (Oracle, Microsoft, and IBM) answer them.