Opening a DR database in Read/Write temporarily using restore points

Opening a DR database in read write mode
Objective of this document is to convert the DR database (Mount state)
into Read Write mode temporarily and restoring it back to sync it up with the
PRIMARY database.
DR Environment
For example  take a  two node clustered DR database as follows,
NAME      DB_UNIQUE_NAME                 OPEN_MODE
———
—————————— ——————–
I****01   DRI****01                      MOUNTED
I****01   DRI****01                      MOUNTED
INSTANCE_NAME    STATUS      
HOST_NAME
—————- ————
——————————–
I****011         MOUNTED      of90.egan.server.com
I****012         MOUNTED      of91.egan.server.com
If the
flashback mode is disabled in the database.
The
Flashback mode has to be enabled to restore the DR after application
installation.
Steps to enable the flashback mode in both the Primary and DR
I****01 database.
1.       
Enabling
Flashback in DR database.
a.       
Cancel the recovery in the standby database.
STANDBY>ALTER DATABASE RECOVER
MANAGED STANDBY DATABASE CANCEL;
b.       
Then activate the FLASHBACK on the standby
database.
STANDBY> alter system set
db_flashback_retention_target=1440 scope=both; 
#### retention value varies
depending on the requirement.
STANDBY>ALTER DATABASE FLASHBACK
ON;
c.       
Verify the flashback mode,
SQL> select flashback_on from
v$database;
2.       
Enabling
Flashback in the Primary database.
a.       
Activate the FLASHBACK on the PRIMARY
database.
PRIMARY> alter system set
db_flashback_retention_target=1440 scope=both;
#### retention value varies depending on the requirement.
PRIMARY> alter database flashback
on;
b.       
Verify the flashback mode,
SQL> select flashback_on from
v$database;
Once
the flashback mode is enabled, we shall go ahead and bring the DR in the read
write mode.
Steps to open the DR database in Read/Write mode
a.       
Stop the recovery in the DR database.
STANDBY>ALTER DATABASE RECOVER
MANAGED STANDBY DATABASE CANCEL;
b.       
Check The MRP status,
STANDBY>select PROCESS,CLIENT_PROCESS,THREAD#,SEQUENCE#,BLOCK#
from v$managed_standby where process = ‘MRP0′ or client_process=’LGWR’;
                                        (or)
host#     ps –ef|grep –imrp
c.       
Creating a restore point to flashback the DR
DB to the old stage & this will help us to bring back as a standby
database.
STANDBY> CREATE RESTORE POINT
stby_fb_dri****01 GUARANTEE FLASHBACK DATABASE;
## stby_fb_dri****01 is the restore point name
d.       
Check the SCN and restore point details in
the DR database,
STANDBY> select NAME,SCN,TIME from
v$restore_point;
e.       
In the Primary database defer the log
shipping to the DR,
PRIMARY> ALTER SYSTEM SET
LOG_ARCHIVE_DEST_STATE_2=DEFER;
f.        
Activate the DR physical standby database and
open it in Read/Write mode,
STANDBY>alter database activate
standby database;
g.       
Check the status of the controlfile_type
after changing the DR database in Read/Write
STANDBY>select CONTROLFILE_TYPE
from v$database;
h.       
Open the DR database in Read/Write mode,
STANDBY> ALTER DATABASE SET STANDBY
DATABASE TO MAXIMIZE PERFORMANCE;
STANDBY> ALTER DATABASE OPEN;
i.        
Opening the DR in node two is optional, if
you would like to open it,
NODE 2 STANDBY>ALTER DATABASE OPEN;
Steps to restore the DR
a.       
Stop the DR database completely.
srvctl stop database –d I****01
b.       
Start one instance to restore the DR to its
old state,
STANDBY>startup mount
STANDBY> FLASHBACK DATABASE TO
RESTORE POINT stby_fb_dri****01;
c.       
Check the controlfile_type of the DR
database,
STANDBY> select controlfile_type
from v$database;
d.       
Change back the DR to Physical Standby
database,
STANDBY> ALTER DATABASE CONVERT TO
PHYSICAL STANDBY;
e.       
Bounce the DR database and bring them to
mount,
STANDBY>shutdown immediate
STANDBY>startup mount
f.        
Enable the log shipping in the primary
database,
PRIMARY> ALTER SYSTEM SET
LOG_ARCHIVE_DEST_STATE_2=ENABLE;
g.       
Drop the restore point on the standby
database,
STANDBY> DROP RESTORE POINT
stby_fb_dri****01;
h.       
Start the MRP in the DR database,
STANDBY>ALTER DATABASE RECOVER
MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

  • January 17, 2017 | 14 views
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