CouchDB is one of those databases that is super simple to get started with and then has its not so obvious “tricks” how to accomplish things that might have felt super natural in another DB. CouchDB is a document oriented database where you query on simple or complex keys, which are produced by you using a secondary-index defined by a map-function (as in map-reduce). It is not a database designed for relational data as graph databases (e.g. Neo4j, OrientDB) or RDBMS. CouchDB is not optimized for handling relations. You can mimic it, but be aware that it can come back and bite you in … ..