DR Switch over steps when DGMRL not working

Primary -

select status,instance_name,database_role from v$database,v$instance;

DR -

select status,instance_name,database_role from v$database,v$instance;

Primary -
alter database switchover to DR_Unique_name verify;


no error message should report which signifies that we are good to go with the switchover.
The alert log on the primary database is the best to watch




Fri Jul 13 15:51:23 2018
alter database switchover to ADR verify
ORA-16474 signalled during: alter database switchover to DR verify...
alter database switchover to ADR verify
Fri Jul 13 15:53:29 2018
SWITCHOVER VERIFY: Send VERIFY request to switchover target ADR
SWITCHOVER VERIFY COMPLETE
SWITCHOVER VERIFY WARNING: switchover target has no standby database defined in LOG_ARCHIVE_DEST_n parameter. If the switchover target is converted to a primary database, the new primary database will not be protected.
ORA-16475 signalled during: alter database switchover to ADR verify...

Primary > alter database switchover to DR-uniquename;

Watch both primery and DR alert logs for any errors.

DR - below should show as Primary

select status,instance_name,database_role from v$database,v$instance;

Primary - below should show as Primary

select status,instance_name,database_role from v$database,v$instance;

to verify the Synch -

Primary(old DR)-
select max(sequence#) from v$archived_log;

DR (Old Primary)-

select max(sequence#) from v$archived_log where applied='YES';