620006 (DBMS-II) Assignment-2 Concurrency Control
Submission Date : 08-03-2011
Q-1. Explain the Following Questions.
1). What is Concurrency Control? Why it is needed ? What is its importance?
2). Explain different problem of Concurrency control with and example?
3). What is Serializability? What is its objective?
4). What is locking? What are the Different types of Lock? Explain different level of locking?
5). How does Locking Protocol work?
6). What are the disadvantage of Basic locking protocal? What is Advantage of two phase locking?
7). How does 2PL work?
8). What is Deadlock? How are deadlock handled? What is deadlock prevention? What is deadlock detection and Recovery? Explain with an Example.
9). What is Timestamp Ordering protocol?
10). How does Timestamp Ordering protocol work? Explain with an example?
11). What is Thomas’s write rule and why is it important? (Ignore Obsolete Write Rule)
12). What are the different phases in a validation based concurrency technique?
13). How does validation based concurrency technique work? (Optmistic Technique)
14). What is cascading rollback? Explain with an Example?
15). Define the terms : Lock Point, Strict 2PL, Starvation
Q.2. Differentiate the following :
1). Dirty Read Vs Unrepeatable Read
2). Serial Schedule Vs Non-Serial Schedule
3). Lost Update Vs Uncommitted Data
4). Starvation Vs Deadlock
Q.3. State whether the following statements are true or false. Justify. No Justification, no marks.
1. Level 1 transaction is the minimum consistency requirement that allows a transaction to be recovered in the event of system failure.
2. There is no deadlock in the timestamp method of concurrency control.
3. Level 0 transactions are recoverable.
4. The objective of concurrency control is to schedule or arrange the transactions in such a way as to avoid any interference.
5. In a shrinking phase, a transaction release all locks and can not obtain any new locks.
