Thanks, I am aware. The powers-that-be won't approve an upgrade (they've fired everyone who knew how), so it's a question of whether we can at least upgrade the DB, or just have to wear the risk of staying on Oracle 12 for however long it takes to migrate the last few apps off so we can decomm it.
If no-one can answer, we'll just have to try it first in Dev and hope it doesn't break anything too badly to repair.