UNIVERSITY EXAMINATIONS: 2013/2014
ORDINARY EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 3202A BIT4306 DISTRIBUTED DATABASES
DATE: APRIL, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO
QUESTION ONE
a) Explain the two design strategies for database systems [3 Marks]
b) Explain the implicit assumptions associated with distributed database
management systems [6 Marks]
c) Examine the different ways used to ensure naming transparency [6 Marks]
d) A reference model can be thought of as an idealized architectural model of the
system. Commercial systems might deviate from reference model; still they are
useful for the standardization process. Describe the different approaches used to
describe a reference model [9 Marks]
e) Explain the dimension for the analysis of distributed systems [6 Marks]
QUESTION TWO
a) Examine the different types of replication and allocation [6 Marks]
b) Discuss how authorization control is facilitated in databases [8 Marks]
c) Describe the three types of integrity constraints/assertions [6 Marks]
QUESTION THREE
a) Outline the benefits of fragmentation [5 Marks]
b) Explain how a fragment allocation problem is formulated [7 Marks]
c) Examine the different levels of DB consistency [8 Marks]
QUESTION FOUR
a) Explain the three phenomena/situations that occur if proper isolation is not
maintained [6 Marks]
b) Discuss using an example the concept of conflict equivalence as used in
distributed databases concurrency control [5 Marks]
c) Discuss the various extensions of the 2PL to DDBMS [9 Marks]
QUESTION FIVE
a) Differentiate between Distributed processing and Cooperative processing
[2Marks]
b) Explain the following Four strategies regarding placement of data
i) Centralized [2 Marks]
ii) Partitioned [2 Marks]
iii) Complete Replication [2 Marks]
iv) Selective Replication [2 Marks]
c) In your own opinion which architecture is suitable for distributed databases
[4 Marks]
d) Query processing is a three step process that transforms a high-level query of
relational calculus/SQL into an equivalent and more efficient lower-level query of
relational algebra. Describe the activities involved in Query processing [6 Marks]
