Quiz:
(1) What is Functional Dependency?
(2) Try to list the usages of FDs.
(3) Given relation r,
| S | R | T |
| 1 | 2 | 3 |
| 1 | 3 | 4 |
| 2 | 1 | 4 |
| 3 | 4 | 5 |
Which one of the following 4 tuples can be inserted into r so that FDs: S -> T and R -> T will not be violated?
| S | R | T | |
| A | 1 | 1 | 2 |
| B | 3 | 1 | 2 |
| C | 2 | 4 | 1 |
| D | 2 | 3 | 4 |
(4) What's the definitions of 1NF, 2NF, 3NF and BCNF?
(5) Let R1 be a relation schema,
with schema(R1) = {STUDENT, POSITION, SUBJECT};
Let F1 = {SJ -> P, PJ -> S}.
What are the superkeys of R1 with respect to F1?
Is R1 in 2NF, 3NF,or BCNF with respect to F1?
(6) Let schema(R2) = {STREET, CITY, POSTCODE};
Let F2 = {SC -> P, P -> C}.
What are the superkeys of R2 with respect to F2?
Is R2 in 2NF, 3NF or BCNF?