Oracle provides a number of Specialty information documents on licensing at this link:

http://www.oracle.com/us/corporate/pricing/specialty-topics/index.html

Out of these, the Licensing Data Recovery Environments document here says:

“Standby and Remote Mirroring are commonly used terms to describe these methods of deploying Data Recovery environments. In these Data Recovery deployments, the data, and optionally the Oracle binaries, are copied to another storage device.

“In these Data Recovery deployments all Oracle programs that are installed and/or running must be licensed per standard policies documented in the Oracle Licensing and Services Agreement (OLSA). This includes installing Oracle programs on the DR server(s) to test the DR scenario.

“Licensing metrics and program options on Production and Data Recovery/Secondary servers must match.”

An interested party raised a question. In his case, the standby database was not using the RAC option, whereas the primary database was a RAC database. 

Would his company still have to pay the license for RAC on the standby as well, even if it was not set up?

The answer: No.  The license is payable only if RAC is set up at the standby database level. However, other database options do need to be licensed for the standby if they are being licensed on the production database, such as the in-memory option, the partitioning option, and so on. 

(Note: The information above is provided as a guideline. For formal licensing requirements, it is always a good idea to confirm with your local Oracle sales representative.)