Data 360: Error "Not able to validate for External DMOs" When creating a Data Graph

When creating a Data Graph, users may encounter the error: "Not able to validate for External DMOs." This occurs when external DMOs are included in a DG but the underlying external Data Lake Objects (DLOs) are not accelerated.

External DMOs can only be included in DGs if all mapped external DLOs are fully accelerated. This constraint ensures that the data graph can access the external data quickly and without delays caused by the absence of a cached copy. Acceleration builds a cached copy of external DLOs in the Data 360, but the process takes time, and the DMO cannot be used in a DG until acceleration is fully complete.

If acceleration is disabled on any external DLO after it has been included in a DG, the data graph will fail. Therefore, disabling acceleration for DLOs in a DG is not allowed, as this is a hard dependency.

Additionally, if an external DMO becomes inaccessible (e.g., due to invalid credentials or removal of the external table), the data graph will fail to materialize, and an error will be displayed. All queries against the DG will also fail in this scenario.

Steps to resolve this include ensuring that all external DLOs are fully accelerated and keeping the DLOs accessible for successful DG materialization.