UNIVERSITY EXAMINATIONS: 2014/2015
ORDINARY EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 1207 PRINCIPLES OF DATABASE DESIGN – DISTANCE
LEARNING
DATE: DECEMBER, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE [30 MARKS]
a) User interface design is an important component during application design. In this
regard outline any six key elements considered when designing a form. [6 Marks]
b) Explain why a database developer will decide to develop a prototype for the database application. [4 Marks]
c) Explain the three phases of database design. [6 Marks]
d) Describe any six roles of a database administrator. [6 Marks]
e) Define the following types of attributes
i) Single valued attribute
ii) Multi valued attribute
iii) Simple attribute
iv) Composite attribute [4 Marks]
f) Briefly explain the function of each of the following data definition language statements
i). SELECT statement
ii). UPDATE statement
iii). INSERT statement
iv). DELETE statement [4
Marks]
QUESTION TWO [30 MARKS]
a) Define an index as used in databases and give one limitation of indexes. [2 Marks]
b) Discuss any four components of a database management system(DBMS). [8 Marks]
c) Compare and contrast between hierarchical and network database models. [4 Marks]
d) State and explain three ways of classifying relationships in a database [3 Marks]
e) Discuss any three concurrency control problems typical in two or more concurrently
executing transactions. [3 Marks]
QUESTION THREE [20 MARKS]
Database concurrency controls ensure that transactions occur in an ordered fashion. The
main function of these controls is to protect transactions issued by different users and/or
applications from the effects of each other. They must preserve the four characteristics of
database transactions: atomicity, isolation, consistency and durability. In this regard:
i). State and explain any four problems that may occur if concurrent transactions with interleaving operations are allowed in an uncontrolled manner. [8 Marks]
ii). Discuss any four ways that can be used to control the concurrency control problems you
explained in [a]. [8 Marks]
iii). State and explain TWO major goals of concurrency control techniques discussed in [b].
[4 Marks]
QUESTION FOUR [20 MARKS]
a) Database security refers to the process of protecting the database against unauthorized access
to or modification of the database, denial of service to authorized users and provision of service to authorized users. Any security measure put in place to protect the database must address three key database security characteristics. Identify and explain these characteristics.
[6
Marks]
b) The following report shows how an inexperienced database developer might create a
table. Your mission is to get into 3rd Normal Form. [14 Marks]
QUESTION FIVE [20 MARKS]
a) Discuss THREE functions of a database view. [ 3 Marks]
b) Given the following relations use appropriate SQL statements to:
i) Display mean age of all the employees. [2 Marks]
ii) Display the employee(s) whose first name begins with F and age is not 29. [4 Marks]
iii) Display employee details if they do not work in human resource department. [3 Marks]
iv) Create a view named employee departments to display employee full name and department name. [4 Marks]
v) Insert a new record in the employee table. [4 Marks]
