если в fast_recovery_area не осталось свободного места и не хочется добавлять дополнительное,
можно почистить архивлоги:

1. удаляем файлы архивлогов
2. чистим видимое место
crosscheck archivelog all;

delete noprompt expired archivelog all;

можно не удалять вручную файлы архивлогов, вместо этого команда:

DELETE NOPROMPT ARCHIVELOG ALL;

Incrementally Updated Backups

The following example shows how an incrementally updated backup can be used.

RUN {
 RECOVER COPY OF DATABASE WITH TAG 'mydb_incr_backup' UNTIL TIME 'SYSDATE - 7';
 BACKUP INCREMENTAL LEVEL 1 FOR RECOVER OF COPY WITH TAG 'mydb_incr_backup' DATABASE;
}

The RECOVER COPY... line will not do anything until the script has been running for more than 7 days. The BACKUP INCREMENTAL line will perform a complete backup (level 0) the first day it is run, with all subsequent backups being level 1 incremental backups. After 7 days, the RECOVER COPY... line will start to take effect, merging all incremental backups older than 7 days into the level 0 backup, effectively moving the level 0 backup forward. The effect of this is that you will permanently have a 7 day recovery window with a 7 day old level 0 backup and 6 level 1 incremental backups. Notice that the tag must be used to identify which incremental backups apply to which image copies.

The following script uses the same method, but includes the archivelog backups and management of obsolete backups.

RUN {
 RECOVER COPY OF DATABASE WITH TAG 'mydb_incr_backup' UNTIL TIME 'SYSDATE-7';
 BACKUP INCREMENTAL LEVEL 1 FOR RECOVER OF COPY WITH TAG 'mydb_incr_backup' DATABASE;
 BACKUP DEVICE TYPE DISK TAG 'mydb_incr_backup' ARCHIVELOG ALL NOT BACKED UP DELETE ALL INPUT;
 DELETE NOPROMPT OBSOLETE DEVICE TYPE DISK;
}