I am going through an audit currently and can say with certainty that it only matters where the Oracle software is installed to determine if a license is require for technology, like database processor and internet application server licenses. You may be able to work with Sales to purchase limited use DR licenses at a discount but would have to ask in the case of a full time stand by fail over site.
I am not aware of any user license impact from creating a DR site.
I think we fall in this category?
Data Recovery Environments using Copying, Synchronizing or Mirroring
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.
or this one?
For the purpose of testing physical copies of backups, your license for the Oracle Database (Enterprise Edition, Standard Edition or Standard Edition One) includes the right to run the database on an unlicensed computer for up to four times, not exceeding 2 days per testing, in any given calendar year. The aforementioned right does not cover any other data recovery method - such as remote mirroring - where the Oracle program binary files are copied or synchronized.
The first has cost while the second has none?
Which of the two is the right setup to use?
If you want a HA environment, you would fall under the Data Recovery Environments using Copying, Synchronizing or Mirroring section. You may be able to work with Sales to get these licenses at a discount compared to regular production licenses.
How about in our PROD server we have also UAT, CRP , DEV instances?