ORA-38706: Cannot turn on FLASHBACK DATABASE logging.

Cause : Your media recovery in not enable (Your database in not in archive log mode). In the case of enable Oracle database flashback on you can get this error message if your database is not in archive log mode.

Action : To raise then error set alter your database in archive log mode.

SQL> ALTER DATABASE FLASHBACK ON;
ALTER DATABASE FLASHBACK ON
*
ERROR at line 1:
ORA-38706: Cannot turn on FLASHBACK DATABASE logging.
ORA-38707: Media recovery is not enabled.


SQL> ALTER DATABASE ARCHIVELOG;

Database altered.

SQL> ALTER DATABASE FLASHBACK ON;

Database altered.