[tomiko_nakamura]

I'm not a big fan of MongoDB, but I don't think the introduction of JSONB in PostgreSQL 9.4 makes it a dud (which does not mean MongoDB is not a dud for other reasons).

JSONB allows you to do a lot of things that people are often doing with MongoDB (or document databases in general), but there are still some features not available in PostgreSQL. Built-in sharding, for example. There are external tools to do that with PostgreSQL, and I do have my doubts about MongoDB (partially because I only hear about the horror stories), and I expect similar features in PostgreSQL 9.5 / 9.6, but at the moment it's not there.

Not sure what you mean by Python examples - you can either fetch the data as 'text' and convert it in the application (e.g. json.loads) or just use psycopg2 with an adapter (http://initd.org/psycopg/docs/extras.html) and you'll get the data as Python dictionaries.

The best source of examples is the official documentation (http://www.postgresql.org/docs/9.4/static/datatype-json.html) and the "NoSQL on ACID" training from Bruce Momjian and Thom Brown (https://wiki.postgresql.org/images/d/de/NoSQL_training_-_pgc...).