1 illustrates
in 12c, the emergence of new features have greatly reduced the complexity of failover and switchover. Only one command can be switched operational role. In previous versions of the database, often require multiple commands to complete before they can switch roles.
Note: Before switching operation is still supported in 12c.
2 Experimental -switchover
2.1 Verify meet switchover
Added a command VERIFY for verification library equipment meets the switchover, if there is an error message, the process can follow the prompts to process information.
SQL> ALTER DATABASE SWITCHOVER TO CNDBA_S VERIFY;
Database altered.
2.2 perform switchover on the main library
If the previous operation is no problem, then perform the following switchover operation.
SQL> ALTER DATABASE SWITCHOVER TO CNDBA_S;
Database altered.
If this step is the error message, proceed according to the prompts, the official document gave a very detailed steps, here I am not simulate error conditions.
Specific information refer to the official document: http://docs.oracle.com/database/121/SBYDB/role_management.htm#SBYDB5171
2.3 Open the new primary library (library prepared original)
SQL> alter database open;
Database altered.
2.4 Preparation of opening a new library (Library of origin)
SQL> STARTUP;
2.5 MRP process starts
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT FROM SESSION;
Database altered.
2.6 to see if the handover success
2.6.1 new main library status
SQL> select database_role,open_mode from v$database;
DATABASE_ROLE OPEN_MODE
---------------- --------------------
PRIMARY READ WRITE
2.6.2 The new library equipment status
SQL> select database_role,open_mode from v$database;
DATABASE_ROLE OPEN_MODE
---------------- --------------------
PHYSICAL STANDBY READ ONLY WITH APPLY
2.6.3 View library equipment MRP process
SQL> select process,status from v$managed_standby;
PROCESS STATUS
--------- ------------
ARCH CONNECTED
ARCH CLOSING
ARCH CONNECTED
ARCH CLOSING
RFS IDLE
RFS IDLE
RFS IDLE
MRP0 APPLYING_LOG
8 rows selected.
Handover success, much more convenient than before. Provided that some of the parameters to be configured standby database, such as standby log, log_archive_dest_n.