Database Security and Authorization MCQs in DBMS

1. : What is the primary goal of deadlock detection in a DBMS?

(A) To prevent transactions from conflicting

(B) To identify and resolve situations where transactions are waiting indefinitely for resources held by each other

(C) To ensure that all transactions are completed successfully

(D) To guarantee that transactions execute in serializable order

2. Which technique is used to detect deadlocks by constructing a resource allocation graph?

(A) Wait-Die scheme

(B) Two-Phase Locking

(C) Resource Allocation Graph (RAG)

(D) Timestamp Ordering

3. In a Resource Allocation Graph, what does a cycle represent?

(A) A successful transaction

(B) A deadlock situation

(C) A high-performance query

(D) A system checkpoint

4. Which of the following is a common strategy for resolving deadlocks?

(A) Ignoring deadlocks

(B) Waiting for transactions to complete

(C) Aborting one or more transactions involved in the deadlock

(D) Increasing the system’s resources

5. Which methods are used to prevent deadlocks rather than detecting them?

(A) Wait-Die and Wound-Wait schemes

(B) Timeout approach

(C) Deadlock Recovery

(D) Two-Phase Locking

6. In the Wait-Die scheme, what happens when a younger transaction requests a resource held by an older transaction?

(A) The younger transaction waits

(B) The younger transaction is aborted

(C) The older transaction is aborted

(D) The system performs a rollback

7. Which deadlock resolution strategy involves selecting and aborting the transaction with the smallest amount of work done or least impact on the system?

(A) Random Selection

(B) Wait-Die Scheme

(C) Minimum Cost

(D) Rollback

8. What is the primary advantage of using a timeout approach for deadlock detection?

(A) It avoids the need for complex algorithms

(B) It ensures transactions are executed in order

(C) It simplifies deadlock detection by assuming that a transaction will eventually timeout

(D) It reduces the overhead of managing transaction logs

9. Which of the following is NOT a characteristic of the Wait-Die scheme for deadlock prevention?

(A) Older transactions can wait for younger transactions

(B) Younger transactions can wait for older transactions

(C) Younger transactions are aborted if they request a resource held by an older transaction

(D) Older transactions are aborted if they request a resource held by a younger transaction

10. In which deadlock detection approach are transactions periodically checked for cycles in the Resource Allocation Graph?

(A) Wait-Die Scheme

(B) Timeout Approach

(C) Periodic Check

(D) Resource Allocation Graph

11. What is the main challenge associated with the wait-for graph in deadlock detection?

(A) Managing high transaction throughput

(B) Detecting cycles within the graph

(C) Allocating resources efficiently

(D) Resolving conflicts without impacting performance

12. Which approach to deadlock resolution involves killing all transactions in the cycle and then restarting them?

(A) Wait-Die Scheme

(B) Timeout Approach

(C) Rollback and Restart

(D) Resource Allocation Graph

13. In a deadlock detection algorithm, which method is used to keep track of transactions and resources to determine if a deadlock has occurred?

(A) Timestamp Ordering

(B) Wait-Die Scheme

(C) Deadlock Detection Algorithm

(D) Multiversion Concurrency Control

14. Which deadlock resolution strategy can potentially lead to reduced performance due to frequent transaction aborts and restarts?

(A) Wait-Die Scheme

(B) Timeout Approach

(C) Rollback and Restart

(D) Two-Phase Locking

15. In the context of deadlock prevention, which technique ensures that no circular wait conditions can occur by enforcing a specific order of resource acquisition?

(A) Wait-Die Scheme

(B) Resource Ordering

(C) Timeout Approach

(D) Multiversion Concurrency Control