The corrective actions that you need to take depend on the state of the commit to switchover operation when the error was encountered.
At this point the primary is in a state identical to that it was in before the commit switchover command was issued. you can proceed with the commit to switchover operation or cancel the switchover operation as outlined in Failure While Preparing the Primary Database .
To continue with the switchover, follow the instructions in Performing a Switchover to a Physical Standby Database for physical standby databases or Performing a Switchover to a Logical Standby Database for logical standby databases, and try again to switch the target standby database to the primary role.
The archived redo log files are not applied to the new standby database after the switchover.
If the underlying file structure is the same on both databases, then the DDL executes on the standby database as expected.
If an error was caused by a DDL transaction containing a file specification that did not match in the logical standby database environment, perform the following steps to fix the problem: In some situations, the problem that caused the transaction to fail can be corrected and SQL Apply restarted without skipping the transaction.
If the last redo data was not transmitted to the standby database, you can manually copy the archived redo log file containing the redo data from the original primary database to the old standby database and register it with the SQL view.
At log switch time, if there are no available standby redo log files that match the size of the new current online redo log file on the primary database: For example, if the primary database uses two online redo log groups whose log files are 100K, then the standby database should have 3 standby redo log groups with log file sizes of 100K.
Also, whenever you add a redo log group to the primary database, you must add a corresponding standby redo log group to the standby database.
Example A-2 shows how to set the initialization parameters so that a single, mandatory, local destination automatically fails over to a different destination if any error occurs.
In most cases, following the steps described in Role Transitions results in a successful switchover.
An example of this might be when available space is exhausted.