In Oracle 12c and later versions, auditing is possible with Unified audit as well as standard auditing. This feature allows role-based auditing. It is possible to audit the activities of any roles by defining role based policies with unified audit.
Create and enable a policy to audit DBA Roles
Create Audit Policy
You can create an audit policy with the below script.
SQL> CREATE AUDIT POLICY role_dba_audit_pol ROLES DBA;
Audit policy created.
Enable Audit Policy
Then, if we enable this policy as follows, audit records of transactions performed by DBA users will now be accessible from the UNIFIED_AUDIT_TRAIL view.
SQL> AUDIT POLICY role_dba_audit_pol;
You can enable Unified Auditing feature by reading the article below.