How do timestamp ordering and optimistic methods differ in concurrency control?

How do timestamp ordering and optimistic methods differ in concurrency control?

Timestamp ordering uses timestamps to manage transaction execution order, while optimistic methods allow transactions to execute without immediate conflict checks.

Can you explain how each method handles conflicts?

In timestamp ordering, if a conflict occurs, the transaction with the older timestamp is allowed to proceed, while the newer one is rolled back. Optimistic methods, on the other hand, check for conflicts only at the end of the transaction, rolling back if any are found.

Which method is generally more efficient?

It depends on the workload. Timestamp ordering can be more efficient in environments with low contention, while optimistic methods may perform better under high contention.

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

Yes, timestamp ordering is often preferred in systems with predictable workloads, while optimistic methods are better for systems with unpredictable access patterns.