How do I delete an image and it’s database entry?

If your configuration’s Database Mode setting is set to “Update Existing Records”, the database record and the image will be deleted when you delete an image from a batch. The Table Name must be an updateable query or table and you must have sufficient permissions for both the database record and the file. 

You cannot delete files with SimpleSearch. To enable retrieval users to change indexes, rename or delete files, use a SimpleIndex Basic license.