Oracle Standby - DB_UNIQUE_NAME

I have an issue. We have an Oracle 11g Database running on AIX. This also has a standby configured. The archives are synced to a directory on the standby server and recovery is performed every 20 minutes to keep the standby in sync.

I observed an anomaly while fixing one of our shell scripts and found that the V$DATABASE table column - DB_UNIQUE_NAME is blank but the parameter is set on both the standby and primary.

Checked an oracle note - 2491642.1 which spoke about this but pointed to PRIMARY_DB_UNIQUE_NAME.

I have checked all the parameters and even RMAN and yet I am baffled at how this happened. Has anyone come across this before and what can be done to remedy it?

Appreciate your feedback.

Thanks so much

Chinedu I.