How to enable oracle flashback in Oracle 11g

How to enable oracle flashback in Oracle 11g

1. To see flashback ON or OFF on running database
   
 SQL> select flashback_on from v$database;

    FLASHBACK_ON
    ------------------
    NO 

2. To get flashback ON

SQL > shut immediate;
SQL > startup mount;
SQL > alter database flashback ON;
SQL > alter database open;

3. To see flashback ON

SQL> select flashback_on from v$database;

FLASHBACK_ON
------------------
YES


Enjoy :)