Assignment-1 Transaction Processing

Submission Date:23-Feb-2011

Q-1. Explain the following questions in detail.

1.       What is a transaction explain with example?

2.       Draw a state diagram and discuss the typical states that a transaction goes through execution?

3.       Explain all transaction property with suitable example?

4.       What is transaction log? What are the typical kind of records in a transaction log?

5.       Explain Transaction Control Statement of SQL with Syntax and Example?

Q-2. Fill in the Blanks.

1.   Collection of operations (for example, all the operations involved in the paymet of telephone bill) that form a single logical unit of work are called_______________.

2.   The ACID properties of a transactions are______, _______, _______and _________.

3.   _______ means that either all operations of the transactions are reflected properly in the database or none are.

4.   _______ means that execution of a transaction in isolation preserves the consistency of the database.

5.  The ____ of the DBMS ensures the atomicity of each transaction.

6.  Ensuring isolation property is responsibility of the _______ of the DBMS.

7.  The SQL statements used for transaction control are _______, _______ and _______.

8.  Transaction Log is a _______ of all _______ and the corresponding changes to the _________.

9.  A Consistent database state is one in which all _________ constraints are satisfied.

Q-3. State Whether the following statements are true or false. Justify your answer

1.  The effect of successfully completed transaction are permanently recorded in the database and must not lost because of subsequent failure.

2.   The transaction consists of all the operations executed between the beginning and end of the transaction.

3.  A transaction that is either committed or aborted is said to be terminated.

4.  Atomic transaction is transaction in which either all actions associated with the transaction are executed to completion, or none are performed.

5.  Log is a record of all transactions and corresponding changes to the database.

6.  The DBMS automatically update the transaction log while executing transactions that modify the database.

7.  A Transaction is said to be in committed state if it has partially committed, and it can be ensured that it will be never aborted.

8. A transaction is a program unit, which can either be embedded within an application program or can be specified interactively via a high-level query language such as SQL.

9. A transaction that changes the contents of the database must alter the database  from one consistent state to another.

Assignment-2 Concurrency Control

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.

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