The questions can come in any order, so make sure you are selecting right option for all questions.
1. What will happen if concurrency control fails?
(a) Lost Update Problem (c) Inconsistency analysis problem / Incorrect summary problem (d) Uncommitted dependency (dirty read) problem / Temporary update problem
2. Which of the following concurrency control techniques allows transactions to execute concurrently by allowing reads to proceed even while writes are in progress, thereby maximizing concurrency and reducing contention?
(a) Optimistic Concurrency Control (OCC)
3. In the context of concurrency control in databases, which of the following strategies ensures that a database transaction will only proceed if it can be executed without conflict, thereby not requiring transaction rollbacks?
(d) Optimistic concurrency control
4. Select the purpose of concurrency control.
(a) To enforce Isolation (b) To preserve database consistency (c) To resolve read-write and write-write conflicts
5. In computer science, __________ is a property of systems in which several computations are executing simultaneously, and potentially interacting with each other.
(b) concurrency
6. Which of the following statements are true regarding the use of multiversion concurrency control (MVCC) in a database system?
(a) MVCC eliminates the need for write locks by keeping multiple versions of data. (c) MVCC can prevent non-repeatable reads and phantom reads without locking. (d) MVCC uses a timestamp ordering protocol to maintain serializability.
7. Determine the need of concurrency control
(a) Lost Updates. (b) Uncommitted Data (d) Inconsistent retrievals
8. Consider a distributed database system that requires both local and global serializability. Which of the following concurrency control mechanisms is specifically designed to maintain global database consistency by ensuring that inter-site transactions are serialized in the same order at all sites?
(b) Distributed timestamp ordering protocol (DTO)
9. Which of the following concurrency control techniques ensures that transactions maintain consistency by preventing the occurrence of phenomena like dirty reads, non-repeatable reads, and phantom reads?
(a) Multiversion Concurrency Control (MVCC)
10. In a database system employing both pessimistic and optimistic concurrency control mechanisms, which of the following scenarios would typically be handled more efficiently by optimistic concurrency control?
(b) Transactions that are mostly read-only and seldom update the database. (d) A real-time system where transaction response time is critical and cannot tolerate delays.