Relational data in the document-oriented NoSQL world

Relational databases have a lot of problems when it comes to dealing with a massive amount of data. Be it speed, efficient processing, effective parallelization, scalability, or costs, relational databases fail when the volume of data starts growing. The other challenge of relational databases is that relationships and schemas must be defined upfront. To overcome these problems, people started with normalizing data, dropping constraints, and relaxing transactional guarantees. Eventually, by compromising on these features, relational databases started resembling a NoSQL product. NoSQL is a combination of two terms, No and SQL. Some people say that it means no relational or no RDBMS, whereas other people say that it is "not only SQL". Whatever the meaning is, one thing is for sure, NoSQL is all about not following the rules of relational databases.

There is no doubt that document-oriented NoSQL databases have succeeded a lot in overcoming...