I applied the current July patch sets to a 11.2 and a 12.1 test database. Now I have a 220.127.116.11.7 and a 18.104.22.168.4 test database. It is helpful to have test databases that are on the most current patch sets and releases. If I see unexpected behavior on some other database I can try the same thing on the patched test databases to see if some patch changed the behavior to what I expect. Also, our production databases are all on 22.214.171.124 or earlier releases so I can check whether the new fully patched 12.1 release has different behavior than our older systems.
Here are the patch numbers:
6880880 – current version of opatch
20760982 – 126.96.36.199.7
20831110 – 188.8.131.52.4
My test environments are on x86-64 Linux.