Oracle Exam 1Z0-083 Topic 3 Question 5 Discussion

A duplicate database is a copy of your target database. With the FOR STANDBY clause, it keeps the same unique database identifier(DBID); If FOR STANDBY not specified it creates a new DBID. The duplicate database can include the same content or only a subset from the source database. It can be in the same host or a separate host. The principal work of the duplication is performed by the auxiliary channels.These channels correspond to a server session on the auxiliary instance on the destination host for backup based duplication. For active database duplication the target channels perform the work of pushing data file copies to the auxiliary instance (if number of allocated target channels is greater than the number of allocated auxiliary channels).