Output all possible SQL statementes in a Rails Application

Question

I have just inherited a medium sized Rails application and I want to try to optimize it right away. I want to start with the database to ensure that indexes are placed where they need to be an so forth. I therefore need to quickly find out all possible SQL statements that ActiveRecord might make so that I can compare that with the database schema and see where immediate optimization can be made.

In short: Is there an equivalent to rake routes which would output all possible SQL templates?