W1-2-60-1-6
JOMO KENYATTA UNIVERSITY OF AGRICULTURE AND TECHNOLOGY
University Examinations 2015/2016
YEAR II SEMESTER II EXAMINATION FOR THE DIPLOMA IN INFORMATION TECHNOLOGY
DIT 0407: DATABASE MANAGEMENT SYSTEMS
DATE: AUGUST, 2016 TIME: 1.5 HOURS
Section A: Compulsory Question (20 Marks)
Question One
a) Describe the entity relational model and use of diagram to aid in your description.
[5 marks]
b) Differentiate between relational and relationship as used in databases. [4 marks]
c) Distinguish between distributed databases and decentralized databases. [4 marks]
d) Elucidate any five reasons for distributed databases. [5 marks]
e) Explain the ways in which implementation of distributed databases affect performance. [2 marks]
Section B: Answer any two questions (20 Marks each)
Question Two
a) Describe what functions are in databases. [2 marks]
b) Distinguish between: [6 marks]
i. System defined functions vs user defined functions
ii. Aggregate functions vs scalar functions
iii. Push replication and pull replication
c) List any four advantages of distributed databases. [4 marks]
d) Discuss any two query optimization tips/options. [4 marks]
e) List any three advantages and one disadvantage of database fragmentation. [4 marks]
Question Three
a) Explain the following SQL features. [6 marks]
i. Triggers
ii. Stored procedures
iii. Views
b) Discuss any two problems associated with concurrent access to databases. [4 marks]
c) Discuss the ACID properties of any transaction. [8 marks]
d) Explain locking as used in concurrently control. [2 marks]
Question Four
a) Discuss the following object oriented databases concepts. [8 marks]
i. Abstract data types
ii. Location transparency
iii. Inheritance
iv. Polymorphism
b) As a database administrator, you may need to automate some administrative tools to enable you free some time for other duties. Elucidate any three administrative tasks that you can automate. [6 marks]
c) List three main databases security principles. [3 marks]
d) Explain any three user access controls that can be used in databases. [3 marks]
