Database Transaction Management MCQs in DBMS

1. What is a transaction in the context of a DBMS?

(A) A type of query execution

(B) A backup process of the database

(C) A sequence of operations performed as a single logical unit of work

(D) A single operation on the database

2. Which property of a transaction ensures that all operations within the transaction are completed successfully or none at all?

(A) Consistency

(B) Isolation

(C) Durability

(D) Atomicity

3. Which ACID property ensures that a transaction leaves the database in a valid state?

(A) Atomicity

(B) Consistency

(C) Isolation

(D) Durability

4. What does the Isolation property in transactions ensure?

(A) Transactions are executed all at once or not at all

(B) The database remains in a consistent state

(C) Transactions do not interfere with each other

(D) All changes are permanent once committed

5. Which property ensures that the changes made by a committed transaction are permanent?

(A) Durability

(B) Consistency

(C) Isolation

(D) Atomicity

6. What is the purpose of the COMMIT statement in a transaction?

(A) To abort the transaction

(B) To make all changes made in the transaction permanent

(C) To start a new transaction

(D) To undo all changes made in the transaction

7. What is a ‘rollback’ in the context of a DBMS?

(A) Saving the changes made by a transaction

(B) Starting a new transaction

(C) Undoing all changes made by a transaction

(D) Ending a transaction

8. Which of the following is used to ensure that a transaction has not been interrupted and is completed successfully?

(A) Rollback

(B) Locking

(C) Checkpoint

(D) Commit

9. What is a ‘deadlock’ in database transaction management?

(A) A situation where a transaction is unable to proceed because it is waiting for a resource held by another transaction

(B) A completed transaction that is waiting for commit

(C) A process of backing up the database

(D) A transaction that has been aborted

10. Which of the following is a concurrency control technique used in DBMS?

(A) Rollback

(B) Two-phase locking

(C) Commit

(D) Checkpoint

11. What is the purpose of a ‘log’ in the context of transaction management?

(A) To store the results of a transaction

(B) To back up the database

(C) To execute a transaction

(D) To keep a record of all transactions and changes to the database

12. In the context of database transactions, what is ‘serializability’?

(A) The ability to execute multiple transactions simultaneously

(B) Ensuring that transactions produce the same result as if they were executed in a serial order

(C) The process of rolling back a transaction

(D) The process of committing a transaction

13. What is the main purpose of using ‘lock’ mechanisms in transaction management?

(A) To ensure database consistency and isolation

(B) To store transaction results

(C) To execute transactions in parallel

(D) To increase transaction speed

14. Which of the following describes the ‘write-ahead logging’ protocol?

(A) Logging is done after the changes are written to the database

(B) Changes are written to the log before they are applied to the database

(C) Logs are written only if the transaction is successful

(D) Logs are written at the end of the day

15. What is the ‘two-phase commit protocol’ used for?

(A) Improving transaction speed

(B) Enhancing database security

(C) Ensuring atomicity in distributed transactions

(D) Reducing the size of the transaction log