I've been thinking along similar lines for my project and the issue i'm running into conceptually is tracking WHICH cache records to invalidate upon POST. Say an HTML list, an HTML detail page, and a full composite object all contain references to the particular item you updated. Single items - the detail page and object are fairly easy to know about, but what about a list view and a grid view that also contain that item. What are your thoughts?
A dependency graph between database tables and pages, no? How to define 'page' depends on the rest of the application, I guess in most frameworks it would be 'module' + 'action'.