http://outworkers.com/blog/post/a-series-on-cassandra-part-1-getting-rid-of-the-sql-mentality
http://outworkers.com/blog/post/a-series-on-cassandra-part-2-indexes-and-keys
http://www.datastax.com/dev/blog/basic-rules-of-cassandra-data-modeling
https://medium.com/@mustwin/cassandra-from-a-relational-world-7bbdb0a9f1d#.4uez1443i