What are some concurrency control techniques?

What are some concurrency control techniques used in databases?

Concurrency control techniques are methods used to manage simultaneous operations on a database without conflicting. Some common techniques include locking, timestamp ordering, and optimistic concurrency control.

Can you explain how locking works?

Locking is a technique where a database restricts access to a resource while it is being modified. There are different types of locks, such as exclusive locks, which prevent other transactions from accessing the locked resource, and shared locks, which allow multiple transactions to read but not modify the resource.

What is optimistic concurrency control?

Optimistic concurrency control assumes that multiple transactions can complete without affecting each other. It allows transactions to execute without locking resources, but before committing, it checks if any other transactions have modified the data. If so, it may roll back the transaction.

What are the advantages of using timestamp ordering?

Timestamp ordering assigns a unique timestamp to each transaction. It ensures that transactions are executed in the order of their timestamps, which helps maintain consistency and avoids conflicts. This method can improve performance in environments with low contention.