A fun in-class exercise... Design a data model for an airline reservation system. You want to be able to answer the following questions: 1) What are all the flights from BOS to SFO tomorrow? 2) What are all the flights from BOS to SFO tomorrow that have at least one seat available? 3) Is flight 237 a week from today full? 4) What are the names of all the passengers on flight 237 a week from today? 5) How many flights has John Q. Salaryman taken within the last 12 months? Feel free to do a bit of work on this before class but if you don't have time, let your fellow students take up the slack! We break up into groups of two teams each. After 20 minutes we reconvene as a group to look at the pluses and minuses of various approaches. Sadly the design of 6-120 doesn't allow us to give each group a blackboard. At the left-hand board (closest to the windows):   and Visilux At the middle board: and Prentice-Rosenfeld At the right-hand board (closest to the door): Chou-Liu-Ma and philg's evil children Board users will write down their work large enough for everyone to see. Pairings who will work on paper: Goggin-Kay-Lau and Ortiz Grall/Bartelma and Lin-Song Jin-Wilkerson and Laraqui-Ogrydziak Paper users will explain how their work differs from what they see on the boards and why. At the very end we'll talk about how data model design affects query performance and how to speed things up with indices.