You Asked
The maximum number of cores before needing RAC licensing is per Cluster or for the sum of the Clusters?
and we said...
The Autonomous Database licensing is per Database instance, and the customer does not have to worry about the number of clusters/nodes that the service will use behind the scenes. So for any ADB with more than 16 OCPUs, customers with BYOL will need a RAC license.
Is this answer out of date? If it is, please let us know via a Comment