How do timestamp ordering and two-phase locking compare in database management?

What are the main differences between timestamp ordering and two-phase locking?

Timestamp ordering is a concurrency control method that uses timestamps to determine the order of transactions, while two-phase locking (2PL) is a locking protocol that ensures transactions acquire locks before accessing data and release them afterward.

Which method is more efficient in handling deadlocks?

Two-phase locking can lead to deadlocks if not managed properly, while timestamp ordering avoids deadlocks by rolling back transactions based on their timestamps.

Can you explain how each method handles transaction conflicts?

In timestamp ordering, conflicts are resolved by comparing timestamps and potentially rolling back the older transaction. In contrast, two-phase locking prevents conflicts by ensuring that transactions hold locks on data until they are completed.

Are there scenarios where one method is preferred over the other?

Yes, timestamp ordering is often preferred in systems with high transaction rates and low contention, while two-phase locking is better for environments where data consistency is critical.