What are the types of locks in SQL?

What are the types of locks in SQL?

In SQL, there are mainly two types of locks: shared locks and exclusive locks. Shared locks allow multiple transactions to read a resource, while exclusive locks prevent other transactions from accessing the resource until the lock is released.

Can you explain shared locks in more detail?

Sure! A shared lock is used when a transaction wants to read data. Multiple transactions can hold shared locks on the same resource simultaneously, allowing them to read the data without interfering with each other.

What about exclusive locks?

Exclusive locks are used when a transaction needs to modify data. When a transaction holds an exclusive lock, no other transaction can acquire either a shared or exclusive lock on that resource until the exclusive lock is released.

Are there any other types of locks?

Yes, there are also update locks and intent locks. Update locks are used to prevent deadlocks when a transaction intends to update a resource, while intent locks indicate that a transaction intends to acquire a lock on a lower level.