*_file_name attribute without extension

When a model has a `Paperclip` attachment attached to it, a column named `<attachment_name>_file_name` is created in the model. Is is possible for a record to not have the file extension in this column when saved? For instance, suppose the attachment is `document`. Then the corresponding column in the database would be `document_file_name`. Can the value of this column be something like `Report`, instead of something like `Report.pdf`? If it was saved as the former, is there a way to serve this file with the extension?