Introduction

TestUC1001 – Access Denied is a common error in Databricks Unity Catalog that prevents users from accessing catalogs, schemas, or tables. This issue arises due to misconfigured permissions, missing role assignments, or incorrect metastore configurations. If not resolved, it can disrupt data access and management workflows.

🚨 Common symptoms:

• Error: “TestUC1001 – Access Denied.”
• Cannot access catalogs, schemas, or tables.
• Permissions denied for certain users or groups.
• Databricks jobs fail due to missing access to Unity Catalog objects.

This guide will help you identify the root cause and fix the TestUC1001 Access Denied issue in Databricks Unity Catalog.

1. Check User Permissions on Unity Catalog

Symptoms:

• Error: “Access Denied for user when accessing catalog or schema.”
• Cannot execute SELECT queries on Unity Catalog tables.

Causes:

• The user or group lacks the necessary permissions to access the catalog or schema.
• Default permissions on Unity Catalog objects are too restrictive.

Fix:

✅ Check current permissions for the catalog, schema, or table:

SHOW GRANTS ON CATALOG my_catalog;
SHOW GRANTS ON SCHEMA my_catalog.my_schema;
SHOW GRANTS ON TABLE my_catalog.my_schema.my_table;

✅ Grant permissions to the user or group:

GRANT USE CATALOG ON CATALOG my_catalog TO `user@example.com`;
GRANT USAGE ON SCHEMA my_catalog.my_schema TO `user@example.com`;
GRANT SELECT ON TABLE my_catalog.my_schema.my_table TO `user@example.com`;

2. Verify Metastore Assignment

Symptoms:

• Error: “No metastore configured for this workspace.”
• TestUC1001 error appears when running SHOW CATALOGS;.

Causes:

• The Databricks workspace is not linked to a Unity Catalog metastore.
• Metastore assignment failed or was not configured properly.

Fix:

✅ Check if a metastore is assigned:

SHOW METASTORES;

✅ If no metastore is assigned, assign one:

databricks unity-catalog metastores assign --metastore-id <metastore-id> --workspace-id <workspace-id>

3. Ensure Clusters and Warehouses Support Unity Catalog

Symptoms:

• Error: “Access Denied on Unity Catalog objects.”
• Queries fail in notebooks and jobs using Unity Catalog tables.

Causes:

• The cluster or SQL Warehouse does not support Unity Catalog.
• Legacy clusters using Hive metastore are incompatible with Unity Catalog.

Fix:

✅ Use Unity Catalog-enabled clusters:

• Go to Databricks UI → Clusters → Advanced Options → Enable Unity Catalog.
• Restart the cluster to apply the changes.

✅ For SQL Warehouses, ensure Unity Catalog is enabled:

• Edit the SQL Warehouse settings to support Unity Catalog.

4. Check Service Principal Permissions (Azure & AWS)

Symptoms:

• Databricks jobs fail with TestUC1001 error.
• Service principals lack access to Unity Catalog objects.

Causes:

• Service principal permissions are not properly configured in Unity Catalog.
• The service principal is not assigned the necessary roles.

Fix:

✅ Grant access to service principals:

GRANT USE CATALOG ON CATALOG my_catalog TO `my-service-principal`;
GRANT SELECT ON TABLE my_catalog.my_schema.my_table TO `my-service-principal`;

✅ In Azure, ensure the service principal has permissions for Key Vault and Storage:

az role assignment create --assignee <service-principal> --role "Storage Blob Data Contributor" --scope /subscriptions/<sub-id>/resourceGroups/<rg>/providers/Microsoft.Storage/storageAccounts/<storage-name>

✅ In AWS, check IAM roles and attach necessary policies:

{
  "Effect": "Allow",
  "Action": ["glue:Get*", "glue:Create*", "s3:GetObject", "s3:PutObject"],
  "Resource": "*"
}

5. Resolve Schema and Table-Level Access Denials

Symptoms:

• Users can access the catalog but not specific schemas or tables.
• TestUC1001 error occurs only for certain objects.

Causes:

• Schema or table-level permissions are not granted.
• The user lacks the USAGE permission on the schema.

Fix:

✅ Grant USAGE permission on the schema:

GRANT USAGE ON SCHEMA my_catalog.my_schema TO `user@example.com`;

✅ Grant SELECT on the specific table:

GRANT SELECT ON TABLE my_catalog.my_schema.my_table TO `user@example.com`;

6. Verify Workspace and Region Support for Unity Catalog

Symptoms:

• Unity Catalog is missing from the UI.
• TestUC1001 errors appear across multiple objects.

Causes:

• The Databricks workspace does not support Unity Catalog in the current region.

Fix:

✅ Check if Unity Catalog is available in your region:

• AWS: Unity Catalog is available in all Databricks-supported regions.
• Azure: Some regions may not yet support Unity Catalog.

✅ Upgrade to a Premium or Enterprise plan if you are on the Standard plan.

7. Troubleshooting Step-by-Step

Step 1: Check User Permissions on Unity Catalog

SHOW GRANTS ON CATALOG my_catalog;

Step 2: Verify Metastore Assignment

SHOW METASTORES;

Step 3: Ensure Clusters and Warehouses Support Unity Catalog

• Use Unity Catalog-enabled clusters and restart them if necessary.

Step 4: Test Service Principal and IAM Permissions

• Grant necessary roles to service principals and IAM roles.

Best Practices to Prevent TestUC1001 Errors

✅ Grant Explicit Permissions on Unity Catalog Objects

• Ensure users and groups have the USAGE and SELECT permissions.

✅ Use Unity Catalog-Enabled Clusters and Warehouses

• Legacy clusters do not support Unity Catalog.

✅ Check and Monitor Permissions Regularly

• Use SHOW GRANTS to monitor access permissions on catalogs, schemas, and tables.

✅ Ensure Proper IAM and Azure AD Role Assignments

• AWS IAM roles and Azure service principals must have the correct permissions.

Conclusion

The TestUC1001 – Access Denied error in Databricks Unity Catalog is primarily caused by missing permissions, incorrect metastore configurations, or unsupported clusters. By checking permissions, verifying metastore assignments, and ensuring cluster compatibility, you can quickly resolve this error and restore access to Unity Catalog objects.