Thanks to Tamzin Oscroft for providing this information.
Remote Diagnostic Agent (RDA) is a command-line-driven data collection framework that can gather product and environmental information to assist in problem diagnosis. Full information on RDA is available in Remote Diagnostic Agent (RDA) – Information Center (DocID 2388643.2)
A new Health Check Validation Engine (HCVE) database has been created for version 19c of the database on Windows, and health checks for lower versions on this platform have also been brought up to date.
Other improvements include:
This release of RDA is bundled with the 2.12.38 release of the Diagnostic Assistant (DA). The DA tool is a command-line interface framework designed to simplify and standardize the end user’s experience with various diagnostic tools, providing a common lightweight extensible interface to multiple collection tools (ADR, RDA, OCM, Explorer, etc.). DA packages can also work with Oracle applications (JDE EnterpriseOne, Siebel, PeopleSoft) as verifiers, providing a basic Java interface to facilitate the user’s data collection.
For more information about DA functionality, refer to Diagnostic Assistant: Information Center (Doc ID 201804.2)
For more information on RDA, review these helpful resources: