If you are on 18.3 (below 18.8) on the ODA stack, you will still have to do 3 upgrades to get to Oracle Database 19c (in particular to Oracle 19.9 as of November 2021).
18.3 –> 18.8
18.8 –> 19.6 (this is the big one as you are upgrading from Oracle Linux 6 to Oracle Linux 7 and upgrading to Grid stack to 19c)
19.6 –> 19.9 (the latest release as of October 2021)
Please see the patching requirements for ODA below:
Comments are closed