Flash back features:-
.ora or pfile parameter required for this features.
How to enable the flash recovery area?
In mount stage set the retention period for the flashback feature.
SQL> alter system set db_flashback_retention_target=
[value] the value is in terms of minutes. Example:-4320 is for 3 days.
SQL> alter database flashback on;
The flashback feature will be enabled for all permanent tablespace. If you are interested in making some tablespace’s flashback feature disable. This can be done by below command.SQL>alter tablespace [x] flashback off;