Create Restore Point and Recover the database using Restore Point

To create a flashback restore point, you must be using FRA and flashback must be turned on.
Check to see if flashback is turned on with the following:

Enabling Flashback Database

Step 1 . Set the parameters

ALTER SYSTEM SET  db_recovery_file_dest_size       = 750G   scope = spfile ;
ALTER SYSTEM SET  db_flashback_retention_target    = 240    scope = spfile ;

{ Default is 1440 minutes i.e. 24 hours. Start with 4 hour retention and this can be changed 
dynamically once we have the stats about how much flash back space we need per hour }

Step 2 . Shutdown the database

$ srvctl stop database –d myracdb

Step 3 . Startup mount the database (one node) and turn on Flash Back

SQL> STARTUP MOUNT;  --- > start only one instance manually
SQL> ALTER DATABASE FLASHBACK ON;
SQL> ALTER DATABASE OPEN;

Step 4 . Make Sure Flashback is Turned ON and shutdown the instance.

SQL> SELECT FLASHBACK_ON FROM v$database ;
SQL> SELECT * FROM v$bgprocess where name='RVWR';
SQL> SHUTDOWN IMMEDIATE ;

Step 5 . Start up RAC instances

$ srvctl start database –d myracdb

Recovery Writer process (RVWR)
The Recovery Writer process is responsible for writing to the flashback logs in the flash recovery area.

These logs are required to restore the database to a previous point in time by using the "flashback" option 
for Oracle databases (Oracle 10g and later).

Create Restore Point

SQL> CREATE RESTORE POINT before_migration GUARANTEE FLASHBACK DATABASE;

SQL> SELECT NAME, SCN, TIME, DATABASE_INCARNATION# DI,GUARANTEE_FLASHBACK_DATABASE,
     STORAGE_SIZE FROM V$RESTORE_POINT WHERE GUARANTEE_FLASHBACK_DATABASE='YES' ;

Recover Dataabse with Restore Point

SQL> startup mount
SQL> flashback database to restore point before_migration;
SQL> SHUTDOWN IMMEDIATE

Set the Oracle environment back to the orignal version, run the following:

SQL> startup mount
SQL> alter database open resetlogs;
SQL> drop restore point before_migration;