Database Management System MCQs with Answers
Practice important Database Management System MCQs with answers and explanations.
Multiple Choice Questions
Q671: In a DBMS, what is the purpose of a lock-based concurrency control protocol?
- A: To allow unrestricted access to database objects
- B: To ensure that transactions are executed serially
- C: To ensure that interleaved transactions have the same effect as serial execution
- D: To prevent any database access during transaction execution
View Answer
C
Q672: What does serializability ensure about a schedule in a DBMS?
- A: It guarantees that the schedule is always complete
- B: It ensures the schedule's effect is identical to some serial schedule
- C: It prevents any form of concurrency
- D: It guarantees no transaction will abort
View Answer
B
Q673: What is a deadlock in the context of transaction management?
- A: A situation where all transactions complete successfully
- B: A cycle of transactions waiting for each other’s locks to be released
- C: A method for preventing transactions from accessing the same data
- D: A method for increasing transaction throughput
View Answer
B
Q674: What property of transactions ensures that incomplete transactions do not affect the database?
- A: Atomicity
- B: Consistency
- C: Isolation
- D: Durability
View Answer
A
Q675: Which locking protocol is known for its two-phase approach?
- A: Strict Two-Phase Locking
- B: Optimistic Locking
- C: Pessimistic Locking
- D: Conservative Locking
View Answer
A
Q676: In Strict Two-Phase Locking, when are all locks released?
- A: When a transaction begins
- B: When a transaction requests a lock
- C: When a transaction commits
- D: When a transaction reads an object
View Answer
C
Q677: A transaction’s effect should be persistent even if the system crashes after completion. This property is known as?
- A: Atomicity
- B: Consistency
- C: Isolation
- D: Durability
View Answer
D
Q678: The acronym ACID stands for Atomicity, Consistency, Isolation, and which other property?
- A: Durability
- B: Dependability
- C: Detectability
- D: Delay
View Answer
D
Q679: In the wait-die scheme for deadlock prevention, what happens if a lower priority transaction requests a lock held by a higher priority transaction?
- A: The lower priority transaction is aborted
- B: The higher priority transaction is aborted
- C: Both transactions are aborted
- D: The system waits for both transactions to complete
View Answer
A
Q680: The main benefit of concurrent execution of transactions in a DBMS is to improve?
- A: Consistency
- B: Throughput
- C: Isolation
- D: Atomicity
View Answer
B