UNIVERSITY EXAMINATIONS: 2016/2017
EXAMINATION FOR THE DEGREE OF MASTERS OF SCIENCE IN
DATA ANALYTICS
MDA5204 CURRENT ADVANCES IN DATABASES
ORDINARY EXAMINATIONS
DATE: JULY, 2017 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [20 MARKS]
a) Describe the following types of spatial queries:
i) Nearness query
ii) Nearest neighbor query
iii) Region query
iv) Spatial join (4 Marks)
b) Computer Aided Design (CAD) and geographic databases use geometric constructs to store
information about how objects are constructed, e.g.: designs of buildings, roads, layouts of
integrated-circuits, etc. Explain THREE of these constructs and illustrate graphically how
they are represented (6 Marks)
c) Multimedia databases are characterized by high data volumes and real-time informationdelivery requirements. Explain FOUR requirements of multimedia databases (4 Marks)
d) Identify three database levels of abstractions and use relevant examples to explain these.
(6 Marks)
QUESTION TWO [15 MARKS]
a) While most databases tend to model reality at a point in time (at the “current” time), temporal
databases model the states of the real world across time. Using appropriate illustration,
describe the following techniques to implement time mapping:
i) Temporal relation
ii) Snapshot
iii) Temporal projection (6 Marks)
b) Binary relationships among entities can be mapped using different cardinality constraints.
Discuss and illustrate any THREE of these cardinality constraints (6 Marks)
c) Database programmers can manipulate persistent data directly. Describe the following
degrees of permanence of object identity
i) Intraprocedure permanence
ii) Intraprocedure permanence
iii) Persistent permanence (3 Marks)
QUESTION THREE [15 MARKS]
a) Consider the schedule below involving a set of transactions: T1, T2, …, T5.
i) Is this schedule serializable? Show the workings to justify your answer (6 Marks)
ii) Describe a situation involving the above transactions that would cause an
inconsistent database state (2 Marks)
Structured types can be used to create tables with composite attributes. Illustrate the creation
of structured data types using SQL, illustrating whether subtypes can be created (4 Marks)
c) Explain the nesting and unnesting of relations and cite the functions involved (3 Marks)
QUESTION FOUR [15 MARKS]
a) Distinguish between the following complex database attributes:
i) Composite attributes and derived attributes (2 Marks)
ii) Single-valued attributes and multivalued attributes (2 Marks)
b) To preserve the integrity of data the database system must ensure atomicity, consistency,
isolation and durability. Explain each of these requirements and use a case of executing
transactions to illustrate (8 Marks)
c) Explain the “shadow database” scheme with respect to recovery management. (3 Marks
