CPSC 304 Database Management Systems ... - Ugrad.cs.ubc.ca

Problem 5: (Exercise 19.7 of the book) Suppose you are given a relation R with
four attributes ABCD. For each of the following sets of FDs, assuming those are
the only dependencies that hold for R, do the following:
(a) Identify the candidate key(s) for R.
(b) Identify the best normal form that R satisfies (3NF, BCNF, or none).
(c) If R is not in BCNF, decompose it into a set of BCNF relations that
preserve the dependencies.
1. C → D, C → A, B → C
2. B → C, D → A
3. ABC → D, D → A
4. A → B, BC → D, A → C
5. AB → C, AB → D, C → A, D → B
RA, DRC and SQL
Problem 6: Consider the following schemas:
Branch (bname, assets, bcity)
Customer (cname, street, ccity)
Deposit (bname, account#, cname, balance)
Borrow (bname, loan#, cname, amount)
Rewrite the English queries below using:
(a) Relational algebra
(b) SQL
1. Find all customers having a loan at the bank and the cities in which they live.
2. Find the largest account balance in the bank.
3. Find all the customers who have an account at all branches located in
Vancouver.
Problem 7: Using the same schemas as in Problem 6, tell what the English
meanings of the following DRC queries are.
1. { < b , l,
c,
a > | < b,
l,
c,
a >∈borrow
∧ a > 1200}
2. { < c > | ∃b,
l,
a(
< b,
l,
c,
a >∈ borrow ∧ a > 1200)}
3. { < c > | ∀x,
y,
z(
¬ ( < x,
y,
z >∈ branch)
∨ z ≠"
Vancouver"
∨(
∃a,
n(
< x,
a,
c,
n >∈ deposit)))}
ER Diagrams and Relational Schema
Problem 8: Consider that the officials in YVR have decided to organize all the
information related to the airport in a DBMS and you have been hired to design
the database. Your first task is to organize the information about the planes
stationed and maintained at the airport. The relevant information is as follows:
2