If you are in the habit of running queries directly on your production database to generate custom reports then you will run into the requirement of having to connect to your Drupal database on the Acquia cloud hosting. One of our clients wanted to do this and this is how we got this working for them.
When you host your Drupal site on the Acquia cloud your site resides on a set of different VPSes that runs Varnish, Apache, MySQL and memcache. Additionally you have your staging server, your development server as well as your production servers - all of them being VPSes.