Automatically update RSS feed XML when database is updated in ASP.Net

Hello,

I am creating a RSS XML of news website for providing news to display news on other website.

I am Creating RSS XML , when ever a news in inserted, and the fileds update my RSS XML, and then inserted into SQL DataBase,.

But i want to know how to update RSS XML when ever a news is edited or updated again in database.

Or 

i want to know if i bind RSS Completely from database evertime at page load, then how to replace old XML file or clear Content to XML, to save news Content from Database.