prevent a file from being downloaded when uploading the latest version

there probably is a setting for this but my issue is - I have a number of databases on a server accessed through my webpage. I want to prevent anyone downloading a database while the new version is being uploaded using smartFTP. Is the a simple way to prevent this from happening and could a measage appear to inform the person downloading that the file is unavailable because a new version is being up loaded. What do other people do?

This is not possible.