Arul

I wanted to measure the time spend for validation/before_save/after_commit while saving a active record object. Is there a gem already available for it.

I have 20+ before_save callbacks for a active record. Is there a way in rails to measure the time spent on each callbacks while saving a object into the store?

I have two models User/Car. User can have many Cars. How do i prevent updates to cars if my user object is invalid? Currently Rails does not wrap the attribute update(cars) in a same transaction as user.