ADVANCED DATABASE SYSTEMS
TIME: 2 Hours
INSTRUCTIONS:
Answer Question ONE and another TWO Questions
QJ.
a) Briefly Explain the two basic database access operation in a transaction
(1 Marks)
b) Describe two differences between a query graph and a query tree (3
Marks)
c) Explain at least two disadvantages of a data dictionary
d) Describe the various stages of query processing (8 Marks)
e) Give a brief description of five aspects of database Survivability (10
Marks)
f) Write a trigger that will reflect after each phone call then there is an
update on the customer's bill. You can make the assumption that the bills to
be updated are already present in the database. In order to do this, you can
create another trigger that creates a bill with an amount of 0 for each
registered customer at the beginning of each month (Assuming you have the
event END _MONTH). (6 Marks)
Q2
a) Explain the purpose of system logs as used in transaction processing
system (2 marks)
b) Explain the phases involved for designing an efficient, useful database (12
Marks)
c) Explain at least three problems which can occur when concurrent
transactions execute in uncontrolled manner (6 Marks)
Q3.
a) Explain the purpose of concurrency control in a transaction processing
system (2 marks)
b) Consider the SQL query select * from employee, department where
employee.dept_id = department.dept_id
TIME: 2 Hours
INSTRUCTIONS:
Answer Question ONE and another TWO Questions
QJ.
a) Briefly Explain the two basic database access operation in a transaction
(1 Marks)
b) Describe two differences between a query graph and a query tree (3
Marks)
c) Explain at least two disadvantages of a data dictionary
d) Describe the various stages of query processing (8 Marks)
e) Give a brief description of five aspects of database Survivability (10
Marks)
f) Write a trigger that will reflect after each phone call then there is an
update on the customer's bill. You can make the assumption that the bills to
be updated are already present in the database. In order to do this, you can
create another trigger that creates a bill with an amount of 0 for each
registered customer at the beginning of each month (Assuming you have the
event END _MONTH). (6 Marks)
Q2
a) Explain the purpose of system logs as used in transaction processing
system (2 marks)
b) Explain the phases involved for designing an efficient, useful database (12
Marks)
c) Explain at least three problems which can occur when concurrent
transactions execute in uncontrolled manner (6 Marks)
Q3.
a) Explain the purpose of concurrency control in a transaction processing
system (2 marks)
b) Consider the SQL query select * from employee, department where
employee.dept_id = department.dept_id
