Oracle - Dataguard Switchover

On Production

SQL> alter system switch logfile

SQL> select  database_role,switchover_status from v$database

Verify the output  , database_role= PRIMARY

                     switchover_status= TO STANDBY

Run the below command to switch PRIMARY database to STANDBY

SQL> alter database commit to switchover to physical standby  with session shutdown

SQL> shutdown immediate

SQL> startup nomount

SQL> alter database mount standby database

SQL> alter system set log_archive_dest_stat_2=DEFER

Note: This Production will become the new Standby

On Standby

SQL>  select  database_role,switchover_status from v$database

SQL> alter database commit to switchover to primary with session shutdown

SQL> shutdown immediate

SQL> startup

Note: This Standby will become the new Production 

On new STANDBY [old Production]

SQL> alter database recover managed standby database using current logfile disconnect