FLASH RECOVERY AREA 10g

The Flash Recovery Area, a new feature in 10g, is a specific area of disk storage that is set aside for retention of backup components such as :-
datafiles
image copies
archived redo logs
control file autobackup copies and etc

Features include:

Centralized Backup Files location - All backup components can be stored in one consolidated disk. The Flash Recovery Area can be configured for use by multiple database instances if so desired.
Automated Disk-Based Backup and Recovery -Once the Flash Recovery Area is configured, all backup components are managed automatically by the Oracle server.

Flashback Logs. The Flash Recovery Area is also used to store and manage flashback logs, which are used during Flashback Backup operations to quickly restore a database to a prior desired state.( I will discuss this in another article)

Oracle recommends that the Flash Recovery Area should be sized large enough to include all files required for backup and recovery. Just make sure you have enough continuous disk space.

When sizing, you need to take into account the RMAN backup retention policy, storage device type that you are using and number of data block changes.

A warning server alert is issued when the flash recovery area is 85% full.
A critical server alert is issued when the flash recovery area is 97% full.
(These percentages can be changed )

You can see the alerts in the alert.log and in DBA_OUTSTANDING_ALERTS.
If the flash recovery area becomes full, an error will be issued.

Setting Up the Flash Recovery Area.
These involve setting up 2 main initialization parameter.

DB_RECOVERY_FILE_DEST_SIZE specifies the total size of all files that can be stored in the Flash Recovery Area.( when reached maximum, it can be changed by alter system)
This parameter has to be set first

DB_RECOVERY_FILE_DEST specifies the physical disk location where the Flashback Recovery Area will be stored. Oracle recommends that this be a separate location from the database's datafiles, control files, and redo logs



ALTER SYSTEM SET db_file_recovery_dest_size = '5G' SCOPE=BOTH;
and then set DB_FILE_RECOVERY_DEST and DB_FLASHBACK_RETENTION_TARGET

ALTER SYSTEM SET db_file_recovery_dest = 'c:\oracle\innotiive\flash' SCOPE=BOTH;
ALTER SYSTEM SET db_flashback_retention_target = 2880;( in minutes)
(It is for retention of flasback logs ).