Postgres is an amazing product, and incredibly stable by virtue of being very mature. You can't go wrong with it and will almost certainly be just fine.
However, you can't quite compare Postgres document support with RethinkDB. You'd really need to play with the product to understand the difference, but think of it this way. You could sort of treat Java as a dynamic language by casting everything to object, it would work just fine, but it is night and day compared to how it would work in Python. The difference between the experience of using Postgres and RethinkDB for JSON data is just as vast. You'd really how to try both before you can viscerally understand how amazing a dedicated JSON environment can be.
RethinkDB is behind Postgres on raw performance and we're still shaking out scalability quirks (see http://rethinkdb.com/stability/) but if you take the long view (a year or so), these will be worked out in on time. I'd encourage you to play with the environment -- it's easy and fun, and see if you like it. Feel free to shoot me an email (slava@rethinkdb.com) and I'll be happy to help you out if you have questions.
Postgres is an amazing product, and incredibly stable by virtue of being very mature. You can't go wrong with it and will almost certainly be just fine.
However, you can't quite compare Postgres document support with RethinkDB. You'd really need to play with the product to understand the difference, but think of it this way. You could sort of treat Java as a dynamic language by casting everything to object, it would work just fine, but it is night and day compared to how it would work in Python. The difference between the experience of using Postgres and RethinkDB for JSON data is just as vast. You'd really how to try both before you can viscerally understand how amazing a dedicated JSON environment can be.
RethinkDB is behind Postgres on raw performance and we're still shaking out scalability quirks (see http://rethinkdb.com/stability/) but if you take the long view (a year or so), these will be worked out in on time. I'd encourage you to play with the environment -- it's easy and fun, and see if you like it. Feel free to shoot me an email (slava@rethinkdb.com) and I'll be happy to help you out if you have questions.