Troubleshoot borderless Lakehouse for Databricks Unity Catalog

This page shows you how to resolve common issues when querying remote data in Databricks Unity Catalog with borderless Lakehouse. For general borderless Lakehouse troubleshooting (including connectivity and routing over private interconnects), see Troubleshoot borderless Lakehouse issues.

Tables are empty or not discovered during refresh

If the catalog background metadata refresh indicates success (such as Refresh successfully completed), but tables in the federated catalog do not appear or listing tables returns 0 items, check the following:

  • EXTERNAL USE SCHEMA privilege: Verify that the Databricks Service Principal has been granted the EXTERNAL USE SCHEMA privilege on the target schemas or catalog in Unity Catalog. Without this privilege, background metadata refresh and credential vending for queries will fail.
  • External data access setting: Verify that External data access is enabled on the Databricks Unity Catalog metastore.
  • External location: Verify that the Databricks Unity Catalog and tables use an external storage location (such as Cloud Storage or Amazon S3) rather than default storage.