I'm planning to upgrade 3 instances of Oracle (all same Oracle Home) from 18.104.22.168 to 22.214.171.124. I'm going through the installer and I get to the question about Upgrade or install just the database software. I only want to upgrade one instance initially and leave the others running on 126.96.36.199 in parallel. My question is, what's the difference between:
Install database software only
Upgrade an existing database
I really don't want to touch the other SIDs on there.