Combine RSS feeds, create database of all links, only push links that are not in database

I subscribe to several New York Times RSS feeds. Over the course of several days there will be the same article sent via multiple RSS feeds. This cause me to get the same link several times in some cases. What I want is to be able to give your multiple RSS feeds. I want all of the links to be added to a database. When a new link comes through one of the RSS feeds I want it to be only passed through if it has not be previously passed through. The database need only keep links that are a month or less old. And I want to access this through a single RSS feed that will be updated as soon as links are made available. Whatever script/file your create I want it on your server.