Scaling relational databases with Apache Spark SQL and DataFrames: 
Relational databases are here to stay, regardless of the hype and the advent of newer databases often called NoSQL databases. The simple reason is that relational databases enforce essential structure, constraints, and provide a nice, declarative language to query data (which we love): SQL!
read more: Opensource.com djsarkar
Supporting Open Source.
Have you tried: Sailing in Africa ?