The other week I posted a three-part series (part 1 [https://www.rittmanmead.com/blog/2014/12/going-beyond-mapreduce-for-hadoop-etl-pt-1-why-mapreduce-is-only-for-batch-processing/] , part 2 [https://www.rittmanmead.com/blog/2014/12/going-beyond-mapreduce-for-hadoop-etl-pt-2-introducing-apache-yarn-and-apache-tez/] and part 3 [https://www.rittmanmead.com/blog/2014/12/going-beyond-mapreduce-for-hadoop-etl-pt-3-introducing-apache-spark/] ) on going beyond MapReduce for Hadoop-based ETL, where I l