Some very helpful MOS Notes got published regarding the upgrade to Oracle Database 18.104.22.168:
- MOS Note: 2173141.1
Complete Checklist for Manual Upgrades to non-CDB Oracle Database 12.2
- MOS Note: 2173144.1
Complete Checklist for Manual Upgrade for Multitenant Architecture Oracle Databases from 12.1. to 12.2.
- MOS Note: 2189854.1
Complete Checklist for Upgrading to Oracle Database 12.2 using DBUA
Furthermore check regularly for Known Issues and Alerts – currently the note has no content but exists already: