I've currently got 3 models: User, Lesson and Course The associations are: * Lesson belongs_to Course * Course has_many Lessons * Course belongs_to User * User has_many Courses Now I'm adding a new model for LessonCompletion, which will be used to track which lessons the user has completed and when. LessonCompletion belongs_to Lesson LessonCompletion belongs_to User User has_many LessonCompletions Lesson has_many LessonCompletions Now the way that this model (LessonCompletion) will be used is primarily on the Course show page in displaying which lessons are done. My question is, should I add another association of LessonCompletion belongs_to Course, Course has_many LessonCompletions or should I just go with Course has_many LessonCompletions, :through => :lessons ? The reason I ask is because I'm wondering if the :through will be very taxing on the system as it will get used a lot.
on 2008-11-24 18:25