how mongodb is more rad than MySQL or Postgresql? anyway NoSQL or SQL you'll still have migration issues if you change the way your application consume datas.

how mongodb is more rad than MySQL or Postgresql? anyway NoSQL or SQL you'll still have migration issues if you change the way your application consume datas. if you have an array of category strings in a document and then you decide you prefer categories to be a dictionary with title keys, you still need to migrate your old datas. NoSQL or SQL same thing. I think what made MongoDB interesting at first place is the use of JSON for storing documents,and the aggregation framework. then you realize simple SQL queries are almost impossible to write as aggregate, so you end up writing map/reduce code which is slow and gold forbid uses javascript. At first you think it solves the impedance mismatch problem,then you realize MongoDB has its own datatypes and you still need an ORM anyway because at some point you need to implement "single table" inheritance because your code is OO. Now about perfomances. They are good yes, but only if you use "maybe" writes. Now in my opinion, CouchDB does far less,but the little it does ,it does it better than MongoDB. curious about CouchBase though. The only reason i'd use Mongo is when using nodejs,cause frankly Mongoose is the most mature ORM on the plateform,and that's quite a bad reason.