RethinkDB and Hadoop solve fundamentally different use cases. RethinkDB is designed for building scalable, realtime apps -- the query language, realtime push f

RethinkDB and Hadoop solve fundamentally different use cases. RethinkDB is designed for building scalable, realtime apps -- the query language, realtime push features (e.g. subscribing to queries), and clustering are purpose-built to help developers build and scale realtime apps. Hadoop is designed for distributed processing of large data sets, and is generally used for analytics workloads and data processing. NoSQL really just means "not using SQL". A lot of projects fit under that umbrella, including graph databases, key-value stores, document databases, and analytics databases, and they all address very different use cases.