CHECKLIST BEFORE SWITCHOVER OPERATION

CHECKLIST BEFORE SWITCHOVER OPERATION
=======================================
Please note

log_archive_dest_state_3 :(archive dest for standby database)
log_archive_dest_state_1 :(archive dest for primary database)

SELECT PROTECTION_MODE FROM V$DATABASE;
SQL> select name,value from v$parameter where name in ('log_archive_dest_1','log_archive_dest_state_1','log_archive_dest_3','log_archive_dest_state_3);

Make sure 'lgwr' and not 'arch' is mentioned here, otherwise new primary database will not open after switchover (if the protection_mode is Maximum availability).

-- on standby database--
SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PHYSICAL STANDBY

-- on primary --
SQL> select database_role from v$database;

DATABASE_ROLE
----------------
PRIMARY

SQL>select name,value from v$parameter where name in ('log_archive_dest_1','log_archive_dest_state_1', 'log_archive_dest_3','log_archive_dest_state_3);
log_archive_dest_state_3
------------------
DEFER --->DO NOT PROCEED.
issue this command : sql> alter system set log_archive_dest_state_3='ENABLE' scope=both;


---- on primary ----
SQL> select distinct status from v$datafile;

STATUS
——-
ONLINE
SYSTEM

If any file(s) are in RECOVER status, DO NOT PROCEED with the switchover


-- on standby database--
SQL> select distinct open_mode from v$database;

OPEN_MODE
———-
MOUNTED --->PROCEED with switchover.



SQL> select distinct open_mode from v$database;

OPEN_MODE
———-
READ ONLY --->DO NOT PROCEED with switchover.

To confirm that logs are being shipped and more importantly the LAST LOG archived has been applied…

---- on primary ----
SQL> select max(SEQUENCE#) “LAST_LOG_GENERATED” FROM V$ARCHIVED_LOG WHERE THREAD# =1 and ARCHIVED=’YES’;

LAST_LOG_GENERATED
——————
3988

-- on standby database--
SQL> select max(SEQUENCE#) “LAST_LOG_APPLIED” FROM V$ARCHIVED_LOG WHERE THREAD# = 1 and APPLIED=’YES’;

LAST_LOG_APPLIED
—————-
3988

---> PROCEED

Thanks