Catch-all term for Data Store-s that are not Relational Data Base-s.
MongoDb, CouchDB, ThingDB, Redis, Tokyo Cabinet, Cassandra, HBase, Volde Mort, Ri Ak...
Apr'2015: some CTO friends are vouching for using Postgre[[SQL]] for this!
Why do this (vs SQL)?
- often easier to scale out to multiple data servers (vs Sharding)
- easier to change Data Model (SQL engines often write-lock entire table as field is added, etc.) (cf Schema-Less)
- less Impedance Mismatch between data and objects (cf ORM) (I think this is least-important)