I'm new to oracle, but I'm looking to upgrade an existing oracle database 220.127.116.11 to 18.104.22.168. Can anyone tell me if this will require wiping my existing database or will it remain intact? Thanks in advance.
Firstly, separate the concepts of database "software installation" from the database "store of data".
22.214.171.124 has changed the upgrade mechanism. Previously you had to install the base version of the software then run an upgrade. 126.96.36.199 is installed as a separate product.
There's a walkthrough here, but the actual steps may vary depending on what your database config is (single node or RAC etc). If you are not confident, make your backup, restore to another machine and test your upgrade first. Only upgrade production when you are confident.
Always take a backup of your database, but you should be able to run the patch to update your existing database. The Patch notes have instructions on what needs to be done (scripts that need to be run after the fact).