The repetition is a good idea but really depends on the audience. In high school Honors Calculus we has one basic proof show up on EVERY weekly quiz until everyone got it right. The rationale was that the proof was so basic to calculus in general that if you didn't get it, you were doomed. Eventually everyone got it right. I managed to get it from the first attempt onward although, for the life of me, I cannot remember that proof now.

Point being that transaction control is so basic to developing robust transactional systems that a little repetition early can save some serious data headaches later.