What is a Transactional Database?

A transactional database is a DBMS where write operations on the database are able to be rolled back if they are not completed properly.

If a transactional database system loses electrical power half-way through a transaction, the partially completed transaction will be rolled back and the database will be restored to the state it was in before the transaction started.

Imagine that a front-end application is sending a customer order to a database system. The front-end application sends the request to product to the customer and subtract the product from inventory. The front-end application is about to send the request to create an invoice for the customer and suddenly the front-end application crashes.

A transactional database can then roll back the partially completed transaction.

An alternative to using a transactional database is to use atomic operations.