Based on the instructions for creating an external table (see: https://docs.databricks.com/data-governance/unity-catalog/create-tables.html#create-a-table) I had assumed that external tables were a way to add an existing object store to Unity Catalog and that once defined they would work just like managed tables. The documentation doesn't seem to specifically describe external tables have behaving differently. In but then I read these two references today:

• “Only files in the exact directory are read; the read is not recursive”
• “When you create a table using this method, the storage path is read only once, to prevent duplication of records…”

see: https://docs.databricks.com/data-governance/unity-catalog/create-tables.html#create-a-table-from-the...