MS SQL Server - 56 - Isolation level MCQ

56 – Isolation level MCQ

1 / 25

1. What is the highest isolation level in SQL Server?

READ UNCOMMITTED

REPEATABLE READ

READ COMMITTED

SERIALIZABLE

2 / 25

2. Which isolation level allows transactions to read uncommitted data from other transactions?

READ COMMITTED

READ UNCOMMITTED

REPEATABLE READ

SERIALIZABLE

3 / 25

3. In SQL Server, which isolation level is the default when creating a new transaction?

SERIALIZABLE

READ UNCOMMITTED

REPEATABLE READ

READ COMMITTED

4 / 25

4. What does the READ COMMITTED isolation level guarantee in SQL Server?

Transactions can read uncommitted data.

Transactions can read committed data only.

Transactions can read and modify data concurrently.

No transactions can read the data concurrently.

5 / 25

5. In SQL Server, which isolation level provides the highest level of data consistency but can lead to more contention?

REPEATABLE READ

READ UNCOMMITTED

SERIALIZABLE

READ COMMITTED

6 / 25

6. What is the primary purpose of the READ UNCOMMITTED isolation level in SQL Server?

To allow only one transaction to access data at a time.

To allow transactions to read uncommitted data.

To allow transactions to read committed data.

To prevent all transactions from accessing data.

7 / 25

7. Which isolation level ensures that a transaction does not read uncommitted data?

READ COMMITTED

SERIALIZABLE

READ UNCOMMITTED

REPEATABLE READ

8 / 25

8. What is the purpose of the SERIALIZABLE isolation level in SQL Server?

To provide the highest level of data consistency.

To allow transactions to read uncommitted data.

To allow transactions to modify data concurrently.

To prevent all transactions from accessing data.

9 / 25

9. Which isolation level allows a transaction to read data without acquiring locks in SQL Server?

READ COMMITTED

REPEATABLE READ

READ UNCOMMITTED

SERIALIZABLE

10 / 25

10. What is the default isolation level in SQL Server when using the “SET TRANSACTION ISOLATION LEVEL” statement?

REPEATABLE READ

READ COMMITTED

READ UNCOMMITTED

SERIALIZABLE

11 / 25

11. What is the purpose of the “SET TRANSACTION ISOLATION LEVEL” statement in SQL Server?

To release all locks held by a transaction.

To specify a transaction's name.

To start a new transaction.

To set the default isolation level for the database.

12 / 25

12. Which isolation level allows a transaction to read data without acquiring locks but may encounter dirty reads?

READ COMMITTED

SERIALIZABLE

REPEATABLE READ

READ UNCOMMITTED

13 / 25

13. What is the primary purpose of the REPEATABLE READ isolation level in SQL Server?

To prevent non-repeatable reads within a transaction.

To prevent all transactions from accessing data.

To allow transactions to read uncommitted data.

To allow transactions to read committed data only.

14 / 25

14. What is the purpose of the “SET TRANSACTION READ ONLY” statement in SQL Server?

To specify a transaction's name.

To release all locks held by a transaction.

To mark a transaction as read-only.

To start a new transaction.

15 / 25

15. Which isolation level ensures that a transaction cannot read data that has been modified but not yet committed by other transactions?

SERIALIZABLE

REPEATABLE READ

READ COMMITTED

READ UNCOMMITTED

16 / 25

16. In SQL Server, what is a non-repeatable read?

When a transaction reads data without acquiring any locks.

When a transaction reads data that has been modified but not yet committed by another transaction.

When a transaction reads the same data multiple times within a single transaction.

When a transaction reads data that is not committed.

17 / 25

17. Which isolation level provides the lowest level of data consistency but allows maximum concurrency in SQL Server?

REPEATABLE READ

SERIALIZABLE

READ COMMITTED

READ UNCOMMITTED

18 / 25

18. What is the purpose of the “SET TRANSACTION READ WRITE” statement in SQL Server?

To release all locks held by a transaction.

To mark a transaction as read-write.

To specify a transaction's name.

To start a new transaction.

19 / 25

19. What does the SERIALIZABLE isolation level guarantee in SQL Server?

That no locks are acquired during a transaction.

That a transaction can read uncommitted data.

That a transaction will be executed in serial order.

That all transactions are serializable.

20 / 25

20. Which isolation level allows a transaction to read and modify data without acquiring locks in SQL Server?

READ COMMITTED

READ UNCOMMITTED

REPEATABLE READ

SERIALIZABLE

21 / 25

21. What is the primary purpose of the READ COMMITTED SNAPSHOT isolation level in SQL Server?

To allow transactions to modify data concurrently.

To prevent all transactions from accessing data.

To provide a consistent snapshot of data to each transaction.

To allow transactions to read uncommitted data.

22 / 25

22. What is the purpose of the “SET TRANSACTION SNAPSHOT” statement in SQL Server?

To create a snapshot of the database.

To specify a transaction's name.

To set the isolation level to SNAPSHOT.

To start a new transaction.

23 / 25

23. Which isolation level in SQL Server is similar to SERIALIZABLE but uses row versioning to provide higher concurrency?

SNAPSHOT

READ UNCOMMITTED

REPEATABLE READ

READ COMMITTED

24 / 25

24. Which isolation level in SQL Server provides a consistent snapshot of data to each transaction and prevents non-repeatable reads?

READ COMMITTED

READ UNCOMMITTED

SNAPSHOT

REPEATABLE READ

25 / 25

25. What is the primary advantage of using the SNAPSHOT isolation level in SQL Server?

It reduces the risk of deadlocks.

It provides the highest level of data consistency.

It provides a consistent snapshot of data without blocking.

It allows multiple transactions to modify data concurrently.

Your score is

MS SQL Server – 56 – Isolation level MCQ