Page 166 of Allen and Bambera list Master-Detail as a best practice. I don't understand why this is a best practice. The term "best practice" suggests there are alternative inferior ways. The section on master-detail just explains a way to do things. How else are your going to store orders and order details? Would it be accurate to say that the best practice here is to normalize your data in contrast to "non-normalized" data like the star schema approach?