You should use the file extension .df for download files.
You can optionally specify a path. If you do not specify a path, the default location is the dbmlsync current working directory,
which is the directory where dbmlsync was started.
Optionally, when creating a download file, you can use the -be option to specify a string that can be validated at the remote
database, and the -bg option to create a download file for new remote databases.