I am starting work on a large project in Rails 3. I want to build the app using both MySql and MongoDB. I already know how to use Rails with MySql, and have found a lot of info about using MongoDB and rails. But what I have not been able to find is any good information on using both MySql and MongoDB together. I was looking at the Mongoid project, and thought it would be good to use, thought I don't know if it is the best solution.
On the Mongoid site under the Installation/Configuration section it talks about using both Mongoid and ActiveRecord together, but it does not explain how.
So, I was hoping someone could tell me either how to set Mongoid and ActiveRecord to work together, or a better solution all together.