When working with Oracle database, the customer has to know about licensing. It is just like with any other product. The problem with Oracle is that all the paid options are included with the database and there is no way to prevent the use of any paid option by mistake. Oracle does not have a product key.
The use of all Oracle options, paid or free, in any database are recorded in the data dictionary. You cannot make any changes to it. The license audit queries this usage and will report on use of every option. The license compliance staff will find out which paid options you are using, how many times each option was used and when was an option last used (date and time of last usage).
So, as a DBA if you want to test an option, say encryption or export compression, first make sure that it does not require a separate license. The license requirements are generally in the product documentation. If it does require license, then ask your manager or someone responsible if your purchase contract has paid for that option or not.
If you do not have license for an option, but still want to test it, make sure you do the testing in a throwaway database. Test the option, drop the database. No problems. If you inadvertently use a paid option in a database, you have following options:
a) Stop using the paid option immediately. Hopefully, in audit, you can make a case that paid option was used by mistake. The license compliance staff might look at last usage date and how many times the paid option was used and might decide to let it go for one time.
b) Be prepared to export all the data from the database, create a new database and import data into it, drop the original database. Make sure you do not use the paid option in the new database. One of my friend works for a big financial group and they had to resort to export/import/drop.
c) Sometimes, it is possible to negotiate with Oracle. In my case, I found that users had created tables with compression which required license for Advance Compression. We did not have that license. Oracle asked if we can drop these tables and re-run audit. Since the tables were created for testing, I was able to drop these tables and Oracle let it go. But, we give Oracle several million dollars worth of business every year, so that might have played a part in it.
Oracle VM license requirements are bit shady and they did catch me by surprise when I learned that with VMWare, Oracle must be licensed for number of CPUs in the VM host and not only for the CPUs used in the VMs on which Oracle was running. That was more than a decade ago. Oracle has this concept of hard partitioning and soft partitioning of VMs. For soft partitioned VMs, you have to buy license for entire host. Oracle has their own VM product which creates hard partitioned VMs. In that case, you do need licenses only for the VMs on which Oracle is running. IMHO, this is anti-competitive, but private companies are free to make their own rules, heck they can write their own constitution...
You can carry out your own license audit periodically. You do not have to engage Oracle to do that. You need only good DBAs. Unfortunately, most places do not care about licensing. Maybe they do not understand how Oracle licensing works or they do not care. Whatever is the reason, I have seen that Oracle will let things slide if the usage is inadvertent and you have stopped using the paid option. However, if you continue to use it and do not pay for it, then you will have a problem.
Here is an anecdote. I once purchased MS Office license key online. It was very cheap. I downloaded MS Office from Microsoft's own website, entered the key and it worked fine. So, I assumed that it was genuine, just like the seller had said. Never had a problem with MS Office updates. Then, one day, I got a new laptop. I tried to transfer the key from original laptop to the new one. It would not work. So, I called Microsoft support and they said that the license key had a problem. I forget the specific details, but they refused to help. Told me to contact the key vendor who had conveniently disappeared. Point is that license is enforced by every vendor, not just Oracle. With Oracle, the product being an enterprise level database, the costs are high and make it to the headlines.