Release : 11.x, 12.x
Component : CA Workload Automation Database Agent
It makes no difference whether you have containers configured for the Oracle database or not as the Database plugin uses the JDBC driver to connect to the database.
For Oracle 12c database, use the service name instead of SID (system identifier) and URL syntax;
jdbc:oracle:thin:@<hostname>:<port>/<service_name>
Note the / instead of : in the URL.
So, update the db.default.url parameter in agent's agentparm.txt and restart the agent for the change to take effect.