Once a transaction has been committed and become durable, it will persist and not be undone. Durability is achieved by completing the transaction with the persistent database system before acknowledging commitment. Provisioning clients only receive SUCCESS responses for transactions that have been successfully committed and have become durable.
The system recovers committed transaction updates in spite of system software or hardware failures. If a failure (for example, loss of power) occurs in the middle of a transaction, the database returns to a consistent state when it is restarted.