Steps verify for Switchover Dataguard to physical standby
Before Switchover the Dataguard in production Server. You need to check the value of switch over column in v$database.
If it having below value then you can go to switch over the primary to DR server. Following values means both Primary and DR are ready for switchover.
1. Verify the Switch over column value.
PRIM>select switchover_status from v$database ;
STANDBY>select switchover_status from v$database ;
Note: If both parameter are in this stage then we have to do the switchover
Switchover status column values meaning as follows:
Not Allowed : from primary or Dr database either its not allowed to switch-over.
Session Active : means active SQL sessions attached to the primary or standby database that need to be disconnected before the switchover operation.
Switchover Pending : means switch-over request has been received but not processed.
Switchover Latent : means switch-over was in pending mode did not complete and went back to the primary database.
To Primary : From Standby Database means: no active sessions present which allowed to switch over to a primary database.
To Standby : From Primary Database means:no active sessions present which allowed to switch over to a standby database.
Recovery Needed : From Standby DB means, it has not received the switch-over request.
2. Verify the gap status.
select status, gap_status from v$archive_dest_status where dest_id = 2;
VALID NO GAP
Note: If standby and primary have gap then resolved it first.
3. Check file location at both side in case of physical standby.
select file_name from dba_data_files;
select file_name from dba_temp_files;
4. Check parameter value of archive destination.
show parameter log
5. If we found the value of switchover is SESSION ACTIVE.
select switchover_status from v$database;
-- Then use with session shutdown clause with switch over command.
PRIM>alter database commit to switchover to physical standby with session shutdown;
Standby>alter database commit to switchover to primary with session shutdown;