You enable Oracle Database QoS Management in a hierarchical-method. Levels 2 and 3 depend on the previous levels being configured.
On the cluster: Required for all operations
On the server pool: Required for any operation upon the node in that server pool
On the database: Required for any operation
If you have multiple databases within the same Oracle RAC cluster, they might not all be managed by Oracle Database QoS Management. If you enable Oracle Database QoS Management for a multitenant database, then Oracle Database QoS Management is enabled for all pluggable databases (PDBs) of that container database (CDB).
To determine if your database is managed by Oracle Database QoS Management, perform the following steps: