# External IDs in Asset Data Insight

To support resources from external systems, you can reference the resources using externally-controllable IDs in the externalId field in Cognite Data Fusion. To learn more, see Define unique IDs with externalId.

# Asset Data Insight

To support changes to hierarchies, Asset Data Insight requires that you use the externalId field when possible, for example, for time series.

If you don't use the externalId field, different areas of Asset Data Insight may not work as expected. For example, a time series without an externalId can not be plotted on a chart.


If the externalId of a resource is changed in CDF, then any references to it will be broken.

Last Updated: 4/30/2020, 6:29:27 AM