CHANGE STANDBY DATABASE PROTECTION MODE

SQL> select protection_mode from v$database;

PROTECTION_MODE
--------------------
MAXIMUM PERFORMANCE

SQL> show parameter log_archive_dest_2

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_2             string     SERVICE=ORCLSTB1 NOAFFIRM ASYN
                         C VALID_FOR=(ONLINE_LOGFILES,P
                         RIMARY_ROLE) DB_UNIQUE_NAME=OR
                         CLSTB1
log_archive_dest_20             string
log_archive_dest_21             string
log_archive_dest_22             string
log_archive_dest_23             string
log_archive_dest_24             string
log_archive_dest_25             string
log_archive_dest_26             string

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_27             string
log_archive_dest_28             string
log_archive_dest_29             string
SQL> show parameter db_unique_name

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
db_unique_name                 string     ORCL
SQL> show parameter log_archive_config

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_config             string     dg_config=(ORCL,ORCLSTB1,ORCLS
                         TB2)
SQL> alter system set log_archive_dest_2='SERVICE=ORCLSTB1 NOAFFIRM ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCLSTB1';

System altered.

SQL> show parameter log_archive_dest_2

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_2             string     SERVICE=ORCLSTB1 NOAFFIRM ASYN
                         C VALID_FOR=(ONLINE_LOGFILES,P
                         RIMARY_ROLE) DB_UNIQUE_NAME=OR
                         CLSTB1
log_archive_dest_20             string
log_archive_dest_21             string
log_archive_dest_22             string
log_archive_dest_23             string
log_archive_dest_24             string
log_archive_dest_25             string
log_archive_dest_26             string

NAME                     TYPE     VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_27             string
log_archive_dest_28             string
log_archive_dest_29             string

SQL> alter system set log_archive_dest_2='SERVICE=ORCLSTB1 NOAFFIRM SYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCLSTB1';

System altered.


SQL> alter database set standby database to maximize availability;

Database altered.

NOTE: You don’t need to shutdown your instance, when you are changing  protection mode from MAXIMUM PERFORMANCE TO MAXIMUM AVAILABILITY.But you need to if you are going to MAXIMUM PROTECTION.

SQL> alter system switch logfile;

System altered.

SQL> select protection_mode from v$database;

PROTECTION_MODE
--------------------
MAXIMUM AVAILABILITY

SQL> archive log list;
Database log mode           Archive Mode
Automatic archival           Enabled
Archive destination           /u01/app/oracle/oraarch/
Oldest online log sequence     239
Next log sequence to archive   241
Current log sequence           241
SQL> select group#,bytes/1024/1024 from v$standby_log;

    GROUP# BYTES/1024/1024
---------- ---------------
     4        52
     5        52
     6        52
     7        52


SQL> select thread#,max(sequence#) from v$archived_log group by thread#;

   THREAD# MAX(SEQUENCE#)
---------- --------------
     1          240

SQL> select protection_mode from v$database;

PROTECTION_MODE
--------------------
MAXIMUM AVAILABILITY



SQL> alter system switch logfile;

System altered.

database switch over using dgmgrl

Perform a switch over test:


ON PRIMARY DB SERVER :

SQL> select name,open_mode,db_unique_name ,DATABASE_ROLE from v$database;

NAME  OPEN_MODE       DB_UNIQUE_NAME      DATABASE_ROLE
--------- -------------------- ------------------------------ ----------------
ORCL  READ WRITE       ORCL      PRIM

ON STANDBY DB SERVER :

SQL> select name,open_mode,db_unique_name ,DATABASE_ROLE from v$database;

NAME  OPEN_MODE       DB_UNIQUE_NAME      DATABASE_ROLE
--------- -------------------- ------------------------------ ----------------
ORCL  MOUNTED       ORCLSTB1      PHYSICAL STANDBY


LETS CONNECT TO DGMGRL AND SWITCH OVER ROLES

DGMGRL> switchover to 'ORCLSTB1';
Performing switchover NOW, please wait...
Operation requires a connection to instance "ORCLSTB1" on database "ORCLSTB1"
Connecting to instance "ORCLSTB1"...
Connected.
New primary database "ORCLSTB1" is opening...
Operation requires startup of instance "ORCLPRIM" on database "ORCL"
Starting instance "ORCLPRIM"...
Unable to connect to database
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

Failed.
Warning: You are no longer connected to ORACLE.

Please complete the following steps to finish switchover:
start up and mount instance "ORCLPRIM" of database "ORCL"


ON OLD PRIMARY DB SERVER (ORCL) :

I have to start it manually coz dgmgrl was unable to connect to lsnr after role transfer.

SQL> startup mount;
ORACLE instance started.

Total System Global Area  885211136 bytes
Fixed Size    2258320 bytes
Variable Size  566233712 bytes
Database Buffers  310378496 bytes
Redo Buffers    6340608 bytes
Database mounted

SQL> select name,open_mode,db_unique_name ,DATABASE_ROLE from v$database;

NAME  OPEN_MODE       DB_UNIQUE_NAME      DATABASE_ROLE
--------- -------------------- ------------------------------ ----------------
ORCL  MOUNTED       ORCL      PHYSICAL STANDBY


LETS CONFIRM THE DB_ROLE BY QUERYING STANDBY DATABASE

SQL> select name,open_mode,db_unique_name ,DATABASE_ROLE from v$database;

NAME  OPEN_MODE       DB_UNIQUE_NAME      DATABASE_ROLE
--------- -------------------- ------------------------------ ----------------
ORCL  READ WRITE       ORCLSTB1      PRIMARY