https://spark.apache.org/docs/2.4.4/sql-getting-started.html
https://spark.apache.org/docs/2.4.4/rdd-programming-guide.html
https://www.linkedin.com/pulse/spark-simplified-certification-study-guide-raki-rahman
https://spark.apache.org/docs/2.4.4/sql-getting-started.html
https://spark.apache.org/docs/2.4.4/rdd-programming-guide.html
https://www.linkedin.com/pulse/spark-simplified-certification-study-guide-raki-rahman