Now, RDBMS and SQL somewhat goes directly against the principles that forced Hadoop to be created in the first place, which is requirement to have a predefined structure (known as a schema) of the data being stored.

FORBES: Combating the Big Data skills shortage

This traditional database platforms, known as relational database management systems (RDBMS) all use a language called SQL (structured query language).

FORBES: Combating the Big Data skills shortage