UNIVERSITY EXAMINATIONS: 2018/2019
EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY/ BUSINESS IT/ APPLIED
COMPUTING
BIT1207A BBIT107 BAC1207 DATABASE SYSTEMS PRINCIPLES
FULLTIME/ PARTTIME/ DISTANCE LEARNING
DATE: AUGUST 2019 TIME: 2 HOURS
Instructions
o Answer question ONE and any other TWO.
o Question One carry 30 Marks, others 20 Marks each.
QUESTION ONE (COMPULSORY)
a) Discuss the five advantages of DBMS (5 Marks)
b) Discuss three responsibilities of DBA. (3 Marks)
c) Write any four properties of a transaction. (4 Marks)
d) Explain various data models with suitable examples for each (9 Marks)
e) For each of the following terms, explain what the term stands for, the essence of
the functions it provides and a set of example SQL statements (at least TWO for
each) that implement these functions:
i. DDL. (3 Marks)
ii. DML. (3 Marks)
iii. DCL. (3 Marks)
QUESTION TWO
a) Read the following scenario:
A company has several departments. Each department has a supervisor and at
least one employee. Employees must be assigned to at least one, but possibly
more departments. At least one employee is assigned to a project, but an
employee may be on vacation and not assigned to any projects.
Draw an ERD diagram showing all possible attributes together with PK and FK.
(10 Marks)
b) Describe the Data Dictionary and give a suitable example (4 Marks)
c) What is data integrity? (2 Marks)
d) What are constraints? Discuss three benefits of constraints (4 Marks)
QUESTION THREE
a). Differentiate between the following concepts as used in databases.
i. Cardinality and degree of a relationship
ii. Primary key and surrogate key
(4 Marks)
b). Consider the flat database below:
i. Identify and discuss three anomalies that may occur in this data base.
(6 Marks)
ii. Convert this table into third normal form.
(6 Marks)
iii. Store the records into the resultant table(s).
(4 Marks)
QUESTION FOUR
a) Discuss, with the help of a diagrams, the database life cycle. (8 Marks)
b) PhoneTech technologies, a company that sells Nokia mobile phones has implemented
a database that tracks details about their stock. The following is one of the table named
Phone located in a database called Cellphones. Use this information to answer the
questions that follow.
i. Write down a SQL DML statement to display Nokia X series. (3 Marks)
ii. Write down a SQL DML statement to remove all Nokia 2690 phones from the
table. (3 Marks)
iii. Write down a SQL DML statement to display the standard deviation on the price.
(3 Marks)
iv. Write down a SQL DML statement to display total price by PhoneType.
(3 Marks)
QUESTION FIVE
a) What is logical data independence and why is it important?
(4 Marks)
b) Differentiate between 2-Tier and 3-Tier database architecture.
(4 Marks)
c) What are the TWO basic database access operations in a transaction
(4 Marks)
d) What is the purpose of concurrency control in a transaction processing system?
(2 Marks)
e) Discuss any THREE database design issues.
(6 Marks)
