A level 0 incremental backup is physically identical to a full backup. The only difference is that the level 0 backup is recorded as an incremental backup in the RMAN repository, so it can be used as the parent for a level 1 backup.A full backup can never be part incremental backup strategy i.e it cannot be the parent for a subsequent incremental backup.
----------
Differential backup, which backs up all blocks changed after the recent incremental backup at level 1 or 0
Cumulative backup, which backs up all blocks changed after the most recent incremental backup at level 0
Note : Cumulative backups are preferable to differential backups when recovery time is more important than disk space, because during recovery each differential backup must be applied in succession. Use cumulative incremental backups instead of differential, if enough disk space is available to store cumulative incremental backups.
----------
Differential backup, which backs up all blocks changed after the recent incremental backup at level 1 or 0
Cumulative backup, which backs up all blocks changed after the most recent incremental backup at level 0
Note : Cumulative backups are preferable to differential backups when recovery time is more important than disk space, because during recovery each differential backup must be applied in succession. Use cumulative incremental backups instead of differential, if enough disk space is available to store cumulative incremental backups.
This is wonderful content ,explained joins in simplest way with very good examples.
ReplyDelete