Magic Multi-Connections

ActiveRecord models are allowed one connection to a database at a time, per class. Ruby on Rails sets up the default connection based on your database.yml configuration to automatically select development, test or production.

But, what if you want to access two or more databases – have 2+ connections open – at the same time. ActiveRecord requires that you subclass ActiveRecord::Base.

That prevents you doing migrations from one database to another. It prevents you using one set of model classes on two or more databases with the same schema.

Magic Multi-Connections allows you to write your models once, and use them for multiple database Rails databases at the same time. How? Using magical namespacing.

http://magicmodels.rubyforge.org/magic_multi_connections/