The are the different types of backups:
• Full backup: All modified blocks associated with the data file are backed up. A full backup is not a backup of the entire database. For example, you can make a full backup of one data file.
• Incremental level 0 backup: This backs up the same blocks as a full backup. The only difference between a level 0 backup and a full backup is that you can use a level 0 backup with other incremental backups, but not a full backup.
• Incremental level 1 backup: This backs up only blocks that have been modified since the previous backup. Level 1 incremental backups can be either differential or cumulative. A differential level 1 backup is the default and backs up all blocks that have been modified since the last level 0 or level 1 backup. A cumulative level 1 backup backs up all blocks that have changed since the last level 0 backup.
• Incrementally updated backup: This first creates an image copy of the data files, after which subsequent backups are incremental backups that are merged with the image copy. This is an efficient way to use image copies for backups. Media recoveries using incrementally updated backups are fast because the image copy of the data file is used during the restore.
• Block change tracking: This is a database feature that keeps track of blocks that have changed in the database. A record of the changed blocks is kept in a binary file. RMAN can use the contents of the binary file to improve the performance of incremental backups: instead of having to scan all modified blocks in a data file, RMAN can determine which blocks have changed from the binary block change tracking.
• Archivelog backups: This performs the backup of the archivelogs and allows for freeing up space in the archivelog directory. Archivelog backups are normally included as part of the data files but can also be run separately to manage the disk space for the archivelogs.
Now that you understand the RMAN architectural components and the types of backups you can make, you are ready to start up RMAN and configure it for your environment.
