DevelopR6-BDD-Rel_et_NoSQL.pdf
http://instagram-engineering.tumblr.com/post/40781627982/handling-growth-with-postgres-5-tips-from
https://muut.com/blog/technology/redis-as-primary-datastore-wtf.html
http://www.sarahmei.com/blog/2013/11/11/why-you-should-never-use-mongodb/
https://www.percona.com/live/mysql-conference-2012/sessions/living-sql-and-nosql-craigslist-pragmatic-approach