There is a typo in the body of this question. It should be “Hot” instead of “hoi”.
Material:
Backup Methods
==============
Hot backup and cold backup are the two methods deployed for a backup.
They are based on the state of the application when the backup is performed.
In a hot backup, the application is up-and-running, with users accessing their data during the backup process. This method of backup is also referred to as an online backup.
A cold backup requires the application to be shut down during the backup process. Hence, this method is also referred to as an offline backup.
The hot backup of online production data is challenging because data is actively used and changed. If a file is open, it is normally not backed up during the backup process. In such situations, an open file agent is required to back up the open file. These agents interact directly with the operating system or application and enable the creation of consistent copies of open files. In database environments, the use of open file agents is not enough, because the agent should also support a consistent backup of all the database components. For example, a database is composed of many files of varying sizes occupying several file systems. To ensure a consistent database backup, all files need to be backed up in the same state. That does not necessarily mean that all files need to be backed up at the same time, but they all must be synchronized so that the database can be restored with consistency. The disadvantage associated with a hot backup is
that the agents usually affect the overall application performance.
Answer:
C. Open file agent.