You only need a license for new backups. A license will be used with the first backup of a client.

As long as you do not delete the save sets/the backup media, you will always be able to recover.

 

To release a license is a bit more complicated. Let me suggest you do the following:

  -  Run nsrls client to verify the number of entries in the client file index (CFI).

  -  Run nsrlic -v and check for the 'connected' Oracle clients

  -  Rename your file index directory for that client

  -  Run nsrim

  -  Run nsrlic -v again. You will hopefully not see the one client any longer. Worst case, restart NW.

  -  Rename the client's CFI directory to the old pathname.

  -  Run nsrls client to verify the entries.

AFAIR this should release an existing client & DB license.