SWITCHOVER

Purpose

You can use this statement to switch primary and standby tenant roles: losslessly switch a primary tenant to a standby tenant, or switch a standby tenant to a primary tenant.

Syntax

ALTER SYSTEM SWITCHOVER TO {STANDBY | PRIMARY}
    [TENANT tenant_name]
    [VERIFY [NOWAIT]];

Parameters

Examples

• Perform a primary-to-standby switchover on primary tenant tenant1, and verify that TENANT_ROLE has changed to STANDBY and SWITCHOVER_STATUS has changed to NORMAL.

  obclient> ALTER SYSTEM SWITCHOVER TO STANDBY TENANT tenant1;
  Query OK, 0 rows affected
  
  obclient> SELECT TENANT_NAME,TENANT_TYPE,TENANT_ROLE,SWITCHOVER_STATUS FROM DBA_OB_TENANTS
      WHERE TENANT_NAME='tenant1';
  +---------------------+-------------+-------------+-------------------+
  | TENANT_NAME         | TENANT_TYPE | TENANT_ROLE | SWITCHOVER_STATUS |
  +---------------------+-------------+-------------+-------------------+
  | t1                  | USER        | STANDBY     | NORMAL            |
  +---------------------+-------------+-------------+-------------------+
  1 row in set
  

• Before performing a primary-to-standby switchover on the primary tenant, run a pre-check to confirm whether the prerequisites for executing the SWITCHOVER statement are met, and return an error immediately if any prerequisite is not met.

  obclient> ALTER SYSTEM SWITCHOVER TO STANDBY VERIFY NOWAIT;
  

References

For more information about the SWITCHOVER statement, see Switchover.