What are some examples of concurrency in databases?

What are some examples of concurrency in databases?

Concurrency in databases refers to the ability to allow multiple transactions to occur simultaneously. Examples include multi-user environments where several users can read and write data at the same time.

Can you explain how locking works in this context?

Sure! Locking is a mechanism to control access to data. When a transaction locks a resource, other transactions must wait until the lock is released to access that resource.

What are the different types of locks?

There are mainly two types of locks: shared locks, which allow multiple transactions to read data, and exclusive locks, which prevent other transactions from accessing the data until the lock is released.

How does deadlock occur in databases?

Deadlock occurs when two or more transactions are waiting for each other to release locks, creating a cycle of dependencies that prevents any of them from proceeding.