Example Of Other/Legacy DB Connection Management & Query Cache

gistfile1.rb

# Assuming you champioin your other DB connection with a class.

module OtherDb
  class Connection < ActiveRecord::Base
    establish_connection :other_db
    self.abstract_class = true
  end
end

# Alway use the connection for other/legacy connections.

module OtherDb
  class SomeModel < OtherDb::Connection
    self.table_name = 'db_table_name'
    self.primary_key = 'view_unique_identifier'
  end
end

# Now let ActiveRecord cache those queries per request/response.

class ApplicationController < ActionController::Base
  
  around_filter :cache_other_db_connection


  protected

  def cache_other_db_connection
    OtherDb::Connection.connection.cache { yield }
  end

end

Not sure how gist pull requests work... https://gist.github.com/4449608