The chapter opened by examining the two circumstances under which you might feel compelled to depart from proper database-design techniques. You learned that breaking the rules is acceptable if you are designing an analytical database; otherwise, you should design the database properly first and then make deliberate decisions to break or bend specific rules. You then learned that the most common reason for departing from proper design techniques is to improve processing performance. Although this is not a satisfactory reason for breaking the rules, there are times when circumstances dictate that you must consider such changes.
We then continued with a discussion of the alternate measures you can take to improve processing performance, such as enhancing or upgrading the hardware and reviewing the implementation of the database. You learned that you should do all you can to improve performance first and depart from proper design techniques only as a last resort. The chapter then closed with a list of items you should record if you need to break the rules.