This week, I have an 11g Data Guard course in Duesseldorf, Germany. This is one of my favorite courses – Data Guard is so cool! All you need is a configuration file for your standby DB and start it NOMOUNT. Then you invoke RMAN and let it do the dirty work:
RMAN> connect target sys/oracle@prima;
RMAN> connect auxiliary sys/oracle@physt;
RMAN> duplicate target database for standby from active database;
This command works without a previous backup of the primary database – an 11g New Feature. In 10g, you simply take an online backup of the primary and then you issue the command
RMAN> duplicate target database for standby;
You may find a more detailed explanation of the creation of a standby database here.