Which of the DBMS component ensures that concurrent execution of multiple operations on the database results in a consistent database state?

Correct option is D

The transaction processing system in a DBMS ensures that the concurrent execution of multiple operations maintains the ACID properties (Atomicity, Consistency, Isolation, Durability) to result in a consistent database state, even under failures or concurrent access.
Information Booster
1. Transaction Processing System:
· Responsible for managing transactions in the database.
· Ensures that concurrent operations do not interfere with each other and maintains database consistency by adhering to ACID properties.
· Examples include scheduling concurrent transactions, locking mechanisms, and implementing recovery processes in case of failures.
2. Role of ACID Properties:
· Atomicity: Ensures all parts of a transaction are completed, or none are, maintaining the database's consistent state.
· Consistency: Guarantees that the database transitions from one valid state to another.
· Isolation: Prevents transactions from interfering with each other during concurrent execution.
· Durability: Ensures committed transactions persist even in the event of a system failure.
3. Example: If two transactions, one adding a record and another deleting the same record, are executed concurrently, the transaction processing system ensures consistency by isolating these operations or rolling back if conflicts arise.
Additional Knowledge
· Concurrency Control Mechanisms: Include locking, timestamp ordering, and optimistic concurrency to ensure isolation.
· Recovery Mechanisms: Include checkpoints and log-based recovery to maintain durability and atomicity.
· Practical Applications: Online banking systems, e-commerce platforms, and reservation systems heavily rely on transaction processing systems.
· Logs: Used to record changes for recovery purposes but do not manage concurrency.
· Buffer Manager: Handles the efficient transfer of data between main memory and storage but is not responsible for maintaining database consistency under concurrent operations.
· File Manager: Manages physical storage of data but does not address transaction-level consistency.