Homework2 -- Due October 19th  beginning of class. No late homework accepted.

First three questions are from H. G-M
 

1. Exercise 3.6.1 Any 4 (also show that the decompositions are lossless join and dependency preserving) (30 points)
2. Exercise 3.6.2 and 3.6.3 (20 points)
3. Exercise 3.5.9 find at least one other minimal cover (basis) for example 3.22. (Do not reproduce what is already in the book; 10 points)
4. Let F = {AB -> C, A -> B}. (a) Find a minimal cover for F. (b) When (a) was given on an exam at a large wester university, more than half the class answered G = {A -> B, B -> C}. Show that answer is wrong by giving a relation that satisfies F but violates G. (20 points)
5. Let F = {AB -> C, A -> D, BD -> C}. (a) Find a minimal cover for F. (b) Give a 3NF, dependency preserving decomposition of ABCD into only two schemes. (c) Does your answer to (b) have a lossless join? (20 points)

Find out what support is available in SQL for the design theory based on functional dependencies.