Enabling FLAHSBACK Database

Enabling FLAHSBACK Database

Database FLAHSBACK option is introduce in oracle 10g version, and it is only available with ENTERPRISE EDITION,if we have STANDARD EDITION or OTHER then you can't use FLAHSBACK DATABASE option. Suppose if we trying to enable FLASHBACK DATABASE option then we are getting below error message

ORA-00439:feature not enabled: string

To check the Flashback database option is enabled, we can check in v$option or v$version data dictionary view

Now if we are on ENTERPRISE EDITION and want to enable FLASHABACK database, so below are steps for this

1. We need to set below three parameters

1. db_recovery_file_dest

For FLASHBACK RECOVERY AREA LOCATION

2. db_recovery_file_dest_size

For FLASHBACK RECOVERY AREA size

3. db_flashback_retention_target

This parameter value specify in MINUTE, default value is 1440 minute. This parameter is use for how far back in time the database may be flashed back.

NOTE: All three parameter are DYNAMIC so no need to bounce database to take effect the parameter value.

Steps for enable flashback database

1. we can check flashback database is enable or not?

select flashback_on from v$database

NO -- means disable
YES -- means enable

2. shutdown the database

SQL>shutdown immediate

3. startup the database in mount mode

SQL> startup mount

4. enable the flashback database

SQL> alter database flashback on;

5. open the database

SQL> alter database open;