Ok, this thread is a mess
I try to clean up things a little:
- You cannot configure any other DB as a direct data source to Cumulocity IoT.
- Cumulocity IoT uses Mongo DB only and it cannot be exchanged by any other database.
- There is no access to Mongo DB directly available.
- Of course you can integrate data of an existing database to Cumulocity but only using the API & correlated SDKs of Cumulocity IoT.
- Those integrations must be built and could run as a microservice or externally.
- For Data offloading (MongoDB → Data Lake) you can use the DataHub. It cannot be used for data integration.
Maybe this article helps: Data integration options with Cumulocity IoT