If you are running several databases, and would like to only share specific databases via ODBC, you can deny users access to other databases via ODBC. You can do so by deselecting the "Allow 4D Open Connections" in the database properties:

1- Connect to the database through a 4D Client.
2- In the Design environment, select Database properties from the file menu.
3- Go to the page "Data control and access."
4- Deselect the option "Allow 4D Open connection."

This setting will take effect the next time the server is restarted.