What are some examples of concurrency control in databases?

What are some examples of concurrency control in databases?

Concurrency control in databases ensures that multiple transactions can occur simultaneously without leading to inconsistencies. Examples include locking mechanisms, timestamp ordering, and optimistic concurrency control.

Can you explain how locking mechanisms work?

Locking mechanisms prevent multiple transactions from accessing the same data simultaneously. There are two main types: exclusive locks, which allow only one transaction to access the data, and shared locks, which allow multiple transactions to read the data but not modify it.

What is optimistic concurrency control?

Optimistic concurrency control assumes that conflicts are rare. It allows transactions to execute without locking resources, but before committing, it checks if any conflicts occurred. If a conflict is detected, the transaction is rolled back.

What are the advantages of using timestamp ordering?

Timestamp ordering assigns a unique timestamp to each transaction. It helps maintain a consistent order of operations, ensuring that transactions are executed in the order they were initiated, which can simplify conflict resolution.