1. LOVELY PROFESSIONAL UNIVERSITY
Model HOME WORK: #4
Code : CSE 351 Course Title: DATABASE SYSTEMS
School: LHST Department: CSE/IT
Name of the faculty member: Monalisa Panigrahi
Class: B.Tech Term: 2 Section: A1802 Batch: 2008
Max. Marks: 5 DOA: 6-04-2011 DOS: 18-04-2011 DOT: 18-04-2011
PART – A
1. Assume that the Banking system is implemented using an RDBMS. What are the concurrency control
measures one has to take, in order to avoid concurrency related problems in the above system? How
can the deadlock be avoided in this system? How can we implement recovery techniques in such a
system?
2. Design a Query processing engine with all the basic functions for RDBMS ?
3. Why Check points are needed in a Recovery System ?
PART – B
4. How does the concept of an object in the object-oriented model differ from the concept of an entity in
the entity relationship model ?
5. In a Schedule S, two transactions T1 and T2 are executing concurrently. The execution order of those
transaction is given below. What are the problems with the concurrency ?

2. Schedule S
T1 T2
Read A
A= A-1000 Read B
B=B+1000
Read B
B=B+500
Read A
Write B A= A+500
Write A
Write B
Write A Commit
Commit

3. 6. Why do database systems support concurrent execution of transactions, in spite of the extra
programming effort needed to ensure that concurrent execution does not cause any problems ?