Oracle Incremental Backup

Incremental backup:2 levels, level 0, and level 1, 0 levels of backup contain all block,1 level backup changes in the data file block, when performing an incremental backup, the first to do a 0-level backup, as the basis for incremental backup.
(1) An INCREMENTAL backup at level 0 backs up all data blocks in Datafiles being backed up.
(2) A Level 1 backup copies only changed blocks. A Level 1 Incremental backup is either differential or cumulative. If Cumulative, RMAN backs up all blocks changed since the most recent level 0 backup. If differential, RMAN backs up blocks updated since the most recent level 0 or Level 1 incremental backup.

A backup strategy as follows:
1. On Sunday, a incremental level 0 tape backup is performed
2. Monday through Saturday, a cumulative incremental level 1 tape backup is performed

A. The backup performed in step 1 backs up all blocks that has ever been in the database
B. The backup performed in step 2 copies all the blocks changed since the most recent level 0 backup

Incremental backups are divided into 2 categories:
Variance increment: Contains all blocks changed since the last incremental backup, the default incremental backup method;
Cumulative increment: Contains all blocks that have changed since the last incremental backup of level 0.

Oracle Incremental Backup