What are the differences between timestamp ordering and locking in databases?

What are the differences between timestamp ordering and locking in databases?

Timestamp ordering and locking are two concurrency control mechanisms in databases. Timestamp ordering uses timestamps to determine the order of transactions, ensuring that they are executed in a consistent manner. Locking, on the other hand, involves placing locks on data items to prevent other transactions from accessing them until the lock is released.

Which method is more efficient in terms of performance?

The efficiency of each method can vary based on the workload and the specific use case. Timestamp ordering can lead to higher throughput in read-heavy environments, while locking may perform better in write-heavy scenarios. However, locking can also lead to deadlocks, which can degrade performance.

Can you explain how deadlocks occur in locking?

Deadlocks occur when two or more transactions hold locks on resources that the other transactions need to proceed. For example, if Transaction A holds a lock on Resource 1 and waits for Resource 2, while Transaction B holds a lock on Resource 2 and waits for Resource 1, neither can proceed, resulting in a deadlock.

How can deadlocks be resolved?

Deadlocks can be resolved using various strategies, such as timeout, where transactions are aborted after a certain period, or by using a deadlock detection algorithm that identifies and resolves deadlocks by rolling back one of the transactions.