Benefit of using Flash Recovery Area for Archive log in oracle database 10g
It is recommended that you take advantage of the FRA to store as many backup and recovery-related files as as possible, including disk backups and archived redo logs.
Some features of Oracle database backup and recovery, such as Oracle Flashback Database and guaranteed restore points, require the use of an FRA. However, having an FRA for use by these features does not force you to use it to store all recovery-related files.
Even when its use is not required, however, the FRA offers a number of advantages over other on-disk backup storage methods. Backups moved to tape from the flash recovery area (via RMAN and media manager) are retained on disk until space is needed for other required files, reducing the need to restore backups from tape. At the same time, obsolete files no longer needed to meet your recoverability goals and files backed up to tape become eligible for deletion and are deleted when space is needed. These deletions are managed by Oracle when space is required. The DBA no longer has to manually delete old backups, and, it is less likely that a DBA accidentally deletes redundancy set files. Note that if backups written to the FRA are not copied via RMAN and media manager to tape, the automatic deletion of obsolete backups does not occur and pre-Oracle10g cleanup methods are required.