A failed swithcover attempt left both databases with a DATABASE_ROLE=PHYSICAL_STANDBY
Steps I followed to recover from the failure and to change the old PRIMARY back to PRIMARY was as follows:
SQL>shutdown immediate
ORA-01092: ORACLE instance terminated. Disconnection forced
Login to sqlplus again as sysdba and do a startup mount
ORACLE instance started.
Total System Global Area 6.8947E+10 bytes
Fixed
Size
2189520 bytes
Variable
Size
2.0670E+10 bytes
Database
Buffers 4.8050E+10 bytes
Redo
Buffers
225488896 bytes
Database mounted.
SQL>
FROM V$DATABASE, V$INSTANCE
/
DATABASE_ROLE
STATUS
OPEN_MODE
DB_UNIQUE PROTECTION_MODE
PROTECTION_LEVEL SWITCHOVER_STATUS
---------------- ------------ -------------------- ---------
-------------------- -------------------- --------------------
PHYSICAL STANDBY MOUNTED
MOUNTED
casprd MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE
RECOVERY NEEDED
Cancel the MRP process. You may receive “ORA-16136: Managed Standby Recovery not active” if the MRP process is not running.
0
SQL>alter database recover managed standby
database cancel;
alter database recover managed standby database cancel
*
ERROR at line 1:
ORA-16136: Managed Standby Recovery not active
SQL>alter database recover managed standby
database finish;
Now switchover to Primary.
SQL>alter database commit to switchover to primary
with session shutdown;
Open the database.
SQL>alter database open;
Confirm DATABASE_ROLE
SQL>
FROM V$DATABASE, V$INSTANCE
/
DATABASE_ROLE
STATUS
OPEN_MODE
DB_UNIQUE PROTECTION_MODE
PROTECTION_LEVEL SWITCHOVER_STATUS
---------------- ------------ -------------------- ---------
-------------------- -------------------- --------------------
PRIMARY
OPEN READ
WRITE
casprd MAXIMUM PERFORMANCE MAXIMUM PERFORMANCE TO
STANDBY
