Flashback

In this article we will describe the step by step instructions on how to enable flashback on Oracle 12c database

1. Enable ARCHIVELOG mode:

SQL> select log_mode from v$database;

LOG_MODE
------------
NOARCHIVELOG

If the database is in NOARCHIVELOG mode, Enable it

alter system set log_archive_dest_1='LOCATION=/u01/app/oracle/arch';
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE ARCHIVELOG;
ALTER DATABASE OPEN;

Check the Database ARCHIVELOG status

SQL> select log_mode from v$database;

LOG_MODE
------------
ARCHIVELOG

2. Set the DB_RECOVERY_FILE_DEST_SIZE and DB_RECOVERY_FILE_DEST

alter system set DB_RECOVERY_FILE_DEST_SIZE=10G;
alter system set DB_RECOVERY_FILE_DEST='/u01/app/oracle/fra';

3. Enable FLASHBACK database

ALTER DATABASE FLASHBACK ON;

4. Check the FLASHBACK database status

SQL> select flashback_on from v$database;

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

Hope this helps..