streaming files in ruby on rails

I just uploaded files(doc &开发者_高级运维 pdf) in my web server(with my coding). I want to stream those files when I click download link on my page.

please share any tutorials or any suggestions?

---

How do you store them? On disk? In database?
The send_file is the api function that sends the file ... Also, read this: http://john.guen.in/past/2007/4/17/send_files_faster_with_xsendfile/

---

Used send_file in ruby..

send_file(file_to_send, :disposition => "attachment")