QMCS 450 - Database Design - EXAM 1

Exam 1

Sample

QMCS 450 - Database Design - EXAM 1

CLOSED BOOK - CLOSED NOTES - Calculators Permitted

65 Minutes - 100 Points

NAME______NAME

1. (9 pts.) Define data. Define information. Describe how they are different.

2. (9 pts.) Define database. What does a database contain? What is the purpose of a database?

3. (9 pts.) Define identifier. What is the usefulness of an identifier in a database? How are identifiers used in the relational model?

4. (9 pts.) What are the advantages of the database approach over the file system approach to storing data?

5. (9 pts.) Define data dependence. Define data independence. Why is data independence such a desirable characteristic in a database?

6. (9 pts.) List the requirements of a generalized database management systems.

7. (15 pts.) Precision Vehicle Incorporated (PVI) produces custom vehicles under contract. The company can manufacture any type of vehicle (such as a car, cab, limo, van, etc.). Orders received by PVI contain details such as type of vehicle, style, and a yes/no checklist for all options available. PVI keeps an inventory of parts to build the most commonly order vehicles with the most commonly ordered options. It must place orders to vendors for all unstocked and out-of-stock items when an order is received. PVI must keep a list of which parts are stocked by which vendors, some parts being available from multiple vendors. The order to the vendor must contain part number, part description, and price. PVI must keep track of each vendor's address and phone number so that orders can be sent and followed up on when late.

a. List all of the main entities

b. For each entity, list all of the main attributes

c. For each entity, determine an attribute or set of attributes that can best function as an identifier

The remaining problems refer to the following tables:

EmployA

ename / age / deptno
adams / 40 / 200
jones / 35 / 200
macy / 38 / 203
smith / 40 / 201

Dept

deptno / deptname / deptloc
200 / billing / 104
201 / payroll / 105
202 / services / 106

EmployB

ename / age / deptno
adams / 40 / 200
baker / 50 / 202
evans / 42 / 202

8. (2 pts.) What is the cardinality of EmployA?

9. (2 pts.) What is the degree of EmployA?

10. (2 pts.) Describe a possible domain for deptno.

11. (7 pts.) What is the result of a natural join between EmployA and Dept?

12. (7 pts.) What is the result of an outer join between EmployA and Dept?

13. (4 pts.) What is the result of EmployA - EmployB

14. (4 pts.) What is the result of EmployA + EmployB

15. (4 pts.)What is the result of EmployA intersect EmployB