Problem

You are trying to migrate your default Hive metastore to Unity Catalog by following the steps in the Upgrade a schema or multiple tables to Unity Catalog (AWS | Azure) documentation.

You have created the necessary storage credential (AWS | Azure) as well as the external location (AWS | Azure). Permissions are correct. You click Create Query for Upgrade and try to run the generated query, but it generates a Failed to create query error.

Failed to create query try again {"message": "Internal Server Error"}

Cause

Create query for upgrade only works when running the command on a warehouse. If you select a cluster instead of a warehouse in Data Explorer, the upgrade query fails to run.

Solution

Ensure you select a warehouse from the drop down menu in the upper right corner of the Data Explorer page before you try to run an upgrade query.