Clearing Flash area logs in DR environment

We need to follow following procedure to clean flash area logs ,It is applicable only when we donot have flash back restore points :
==================================================================Step 1 : Cancel the mrp process :
=======================================
alter database recover managed standby database cancel;

Step 2 : shutdown the database using shutdown immediate
========================================================
shutdown immediate;

Step3 : SQL > Start no mount

Step 4 :SQL > alter database mount standby database

Step 5 :SQL > alter database flashback off; /#this command will clear flash back logfiles #/

Step 6 :SQL > alter database flashback on ;/#Re enabling flash recover /

Step 7 : If possible restart db again not mandatory.










Example :
==========
We don't have flash back restore points here :
===============================================

INSTANCE_NAME STARTUp Time STATUS
---------------- ---------------- ------------
hytprod91 2010.10.27:03:52 MOUNTED

SQL> SELECT NAME, SCN, TIME, DATABASE_INCARNATION#, GUARANTEE_FLASHBACK_DATABASE,STORAGE_SIZE FROM V$RESTORE_POINT;

no rows selected


FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .08 0 1
ONLINELOG 0 0 0
ARCHIVELOG 0 0 0
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG 99.91 76.65 1236

6 rows selected.

SQL> alter database recover managed standby database cancel;


Database altered.

SQL> SQL> shutdown immediate;
ORA-01109: database not open


Database dismounted.
ORACLE instance shut down.

SQL> startup nomount;
ORACLE instance started.

Total System Global Area 1610612736 bytes
Fixed Size 2182600 bytes
Variable Size 379367992 bytes
Database Buffers 1224736768 bytes
Redo Buffers 4325376 bytes
SQL> alter database mount standby database;

Database altered.

SQL> select flashback_on from v$database;
select * from V$FLASH_RECOVERY_AREA_USAGE;
FLASHBACK_ON
------------------
YES

SQL>

FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .08 0 1
ONLINELOG 0 0 0
ARCHIVELOG 0 0 0
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG 99.91 76.61 1236

6 rows selected.

SQL> alter database flashback off;

Database altered.

SQL> SQL> SQL> SQL> SQL> select * from V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .08 0 1
ONLINELOG 0 0 0
ARCHIVELOG 0 0 0
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG 0 0 0

6 rows selected.

SQL> alter database flashback on;
alter database flashback on
*
ERROR at line 1:
ORA-01153: an incompatible media recovery is active


SQL> alter database recover managed standby database cancel;


Database altered.

SQL> SQL> SQL> SQL> alter database flashback on;

Database altered.

SQL> select * from V$FLASH_RECOVERY_AREA_USAGE;

FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .08 0 1
ONLINELOG 0 0 0
ARCHIVELOG 0 0 0
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG .05 0 1

6 rows selected.

SQL> select flashback_on from v$database;

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

SQL> shut immediate;
ORA-01109: database not open


Database dismounted.
ORACLE instance shut down.
SQL> startup nomount;
ORACLE instance started.

Total System Global Area 1610612736 bytes
Fixed Size 2182600 bytes
Variable Size 379367992 bytes
Database Buffers 1224736768 bytes
Redo Buffers 4325376 bytes
SQL> alter database mount standby database;

Database altered.

SQL> select flashback_on from v$database;
select * from V$FLASH_RECOVERY_AREA_USAGE;

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

SQL>
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
------------ ------------------ ------------------------- ---------------
CONTROLFILE .08 0 1
ONLINELOG 0 0 0
ARCHIVELOG 0 0 0
BACKUPPIECE 0 0 0
IMAGECOPY 0 0 0
FLASHBACKLOG .05 0 1

6 rows selected.