google base feel location of feed file

As I understand it neither the google base or google sitemap have a location they store the sitemap. If that is incorrect, where are they?
If it is a fact they don't store a feed file, doesn't it seem like it should for speed purposes? When I run the google base it does show quite a bit of a slowdown on the store side.

Mike

yes, if your store is pretty huge, it will be slowed down on that page where it fetch your data. You might want to use a caching extension to do the job