Lokesh M

 Profile Answers by Lokesh M Questions by Lokesh M

• Dec 6th, 2011

 

Online backup also known as hot backup / open backup can be performed even the database is open and while users are working and is available for read and write activity. To perform Online backup, the database needs to be in ARCHIVELOG mode and also requires redo log backup to make the database consistent. On-line backups are less disruptive. They do not require the database to be shutdown and hence there will be no downtime. Therefore Online backup are suitable when the database needs to be up and running all the time.

An Offline backup also known as cold backup / closed backup is performed after the database has been closed and shutdown. The backup is taken when the database is not running and is not available to its users. During offline backups it is not necessary for the database to be in ARCHIVELOG mode. Archived redo logs are not required to make the database consistent. Offline backup are suitable when there are times during which there will be no database activity. This period can be utilised to take Offline backup.