Dynatrace provides you with a framework that you can use to extend your application observability into data acquired directly from your Oracle Database layer: here
We understand that we do have a framework for Oracle monitoring, in this request we are trying to understand do we have any plug-in specific to Oracle Enterprise Manager Server which already monitors the Database and how Dynatrace could get those metrics from OEM servers for effecting monitoring from Dynatrace.
If you don't find the metrics you are interested in in the plugin pointed out by a colleague above, then you can write a simple extension that uses the REST API for Oracle Enterprise Manager to retrieve the metrics you are interested in. You can then put these metrics into Dynatrace using Metric Ingest.
You can then build alerts, notifications, dashboards, etc. on these metrics.
Hope it helps!