> Data should be stored as normalized as possible, but queries are supposed to denormalize to present information in the desired format.
But the desired format usually isn't a square, flat table. Usually the data has structure and you want to preserve that structure when you're displaying, not just having it hidden in the database. E.g. you might want to show a heading for each professor and then a list of classes taught by that professor. Getting back a flat table with n duplicate copies of the professor's information is a step backwards.
But the desired format usually isn't a square, flat table. Usually the data has structure and you want to preserve that structure when you're displaying, not just having it hidden in the database. E.g. you might want to show a heading for each professor and then a list of classes taught by that professor. Getting back a flat table with n duplicate copies of the professor's information is a step backwards.