NoSQL databases (Not Only “Structured Query Language”)
SQL databases – Relational and OLAP
Non-SQL databases – Key value, Column-Family, Graph, Document
Non-SQL, or non-relational, databases are still in rapid growth stage versus the already matured SQL stores. The pro of non-SQL databases, thanks to the open-source innovations from Hadoop since 2005, is their free upfront investment and flexible structures, enabling infinite more data that do not fit into a neat table to be captured.