Christopher L. Everett wrote:
More commonly you would combine TTL with invalidation. You use invalidation for the simple stuff, where people need to make instant updates they can see, and you use TTL to catch everything else.I see where one could combine polling and invalidation, for instance by having empty files representing a page that get touched when the data for them go out of date.
Tracking dependencies gets difficult quickly, and that's why almost no one does it. TTL is very efficient, if you can live with data being out of sync for a little while.But again, there is the issue of mapping changed data onto dependent pages.
- Perrin
