Also of note is that stored procedures are supported in a variety of languages, including Javascript, so it's quite easy to handle cases where the surprisingly broad range of core JSON functions and operators [1] doesn't include what you need.
PostgreSQL has also recently added a key-value store type [2] with semantics reminiscent of Redis. The impression I get is that they're gunning for the NoSQL kids in general, and this pleases me; while I grant it is sometimes possible and necessary to obtain new insight in a field by ignoring all that's gone before, I very much doubt this is one of those times, and I am therefore delighted to see a properly engineered database engine gain more or less the entirety of the features which draw interest to the NoSQL crowd in the first place.
That is extremely interesting. So it looks like you can store a JSON type as well as a KV datatype in Postgres! And it looks like it is relatively easy to convert between the two.
This leaves only performance. I think I'm still confused around this area - why do people say that non-relational technologies like MongoDB are faster than relational databases?
PostgreSQL has also recently added a key-value store type [2] with semantics reminiscent of Redis. The impression I get is that they're gunning for the NoSQL kids in general, and this pleases me; while I grant it is sometimes possible and necessary to obtain new insight in a field by ignoring all that's gone before, I very much doubt this is one of those times, and I am therefore delighted to see a properly engineered database engine gain more or less the entirety of the features which draw interest to the NoSQL crowd in the first place.
[1] http://www.postgresql.org/docs/9.3/static/functions-json.htm... [2] http://www.postgresql.org/docs/9.3/static/hstore.html