What is the biggest downside of using journaling as part of a backup restoration process?

Journaling replays transactions, which can take an extended period of time if the time between the last backup and the data loss event was longer and there was a high volume of transactions. Journals typically minimize the amount of transaction data that is lost; they can be encrypted, although care must be taken to ensure that they can be recovered; and journaling is used with live databases to ensure transactions are recoverable to as close to the point in time of a data loss event as possible.