How to hybrid Mysql and MongoDB in Play framework?

I am writing an micro-blogging application using the flask framework . Currently I am using mongoDB as my database . Would it be a good decision to use mongo or stick to a tried and tested solution like MySQL or postgres?

• Answer:

  It really won't matter. Each of these DB options are going to have things to they do and don't do well. And they make different trade-offs in terms of features like data size and querying options. But if you look at the architecture of Twitter (the micro-blogging application), you will see that they are currently (2014) using multiple databases for different purposes: http://highscalability.com/blog/2013/7/8/the-architecture-twitter-uses-to-deal-with-150m-active-users.html On top of Redis and Queue system, they have Storm (http://storm.apache.org/) and all kinds of other tools to keep the service running. So how big is this really going to be? None of the DBs above will take you to 1000 servers without lots of other technologies in between. But is your service ever going to be bigger than a few Terabytes of data? Because with that much data, we can just drop it all on a big server and it won't really matter either way.