Another observation: Environment variable ORACLE_UNQNAME not defined

I had posted an article on same message few days back:

http://vishalorcl.blogspot.com/2011/06/environment-variable-oracleunqname-not.html

Strange, today I gave same command without setting ORACLE_UNQNAME and it works without that error message.

$ echo $ORACLE_UNQNAME

$ emctl status dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.2.0.2.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
https://****************:1158/em/console/aboutApplication
Oracle Enterprise Manager 11g is running.
------------------------------------------------------------------
Logs are generated in directory /oracle/product/11.2.0/***************_RU11852/sysman/log

If I unset ORACLE_SID then I am receiving same message that "Environment variable ORACLE_UNQNAME is not defined".

From this, so far, I would say on standalone database if either of ORACLE_SID or ORACLE_UNQNAME is set then you should not receive that message.

For RAC, you should have ORACLE_UNQNAME set to db_unique_name value.