UNIVERSITY EXAMINATIONS: 2012/2013
EXAMINATION FOR THE BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY
BIT 4306 DISTRIBUTED DATABASES
DATE: AUGUST, 2013 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and Any Other TWO Questions
QUESTION ONE
a) Examine the main differences between homogeneous and heterogeneous DDBMS
[6Marks]
b) Discuss the main architectures used to implement DDBMS. [8 Marks]
c) Examine the main concepts addressed in developing a distributed database system
[8 Marks]
d) Explain the rules used to check if fragmentation has been done correctly. [8 Marks]
QUESTION TWO
a) Explain the relationship between the following concepts. [9 Marks]
i) Distributed computing system
ii) Distributed database
iii) Distributed database management system
b) A distributed database management system (DDBMS) is applicable in a range
of processes. Discuss some of the critical areas that requires DDBMS. [8 Marks]
c) Using an example define the term transaction as used in a distributed database
system. [3 marks]
QUESTION THREE
a) Discuss the main benefits and disadvantages that are brought about by distributed
database system in an organization. [8 marks]
b) Distributed database system like any other system has complicating factors which
makes many organizations unable to implement it. Discuss these factors.
[6 marks]
c) Discuss the 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). [6 Marks]
QUESTION FOUR
a) Discuss the three main functions of semantic data control. [9 Marks]
b) Using an example explain how a clerk can use a query to find the names of
employees who have been working on project P1 for 12 or 24 months?. [4Marks]
c) Discuss the various states a transaction goes through. [7 Marks]
QUESTION FIVE
a) Discuss the properties of transactions in a distributed system. [8 marks]
b) Explain the term deadlock as used in distributed systems. [2 marks]
c) What is the meant by the term Reliable DDBMS
d) Discuss the two ways used by the Local Recovery Management (LRM) to deal with
update/write operations. [6 marks]
e) DDBMS like any other system can experience some failures. Explain some forms of
failures that are most likely to be encountered. [4 marks]
