Most Rails applications out there in the world deal with the manipulation and presentation of data. So the speed of our application is proportional to how fast we can work with data. Rails is good with presenting data. And our Database is the one who is good at processing data. But we sometimes make the mistake of just using the database as a file cabinet, and using ruby to process. The database is built for crunching data and returning to us the results that we need. This talk is about how to optimize your database so as to speed up your existing Rails application.