A determination can be made of how changes to underlying data affect the value of objects. Examples of applications include: caching dynamic Web pages; client-server applications whereby a server sending objects (which are changing all the time) to multiple clients can track which versions are sent to...http://www.google.com.tw/patents/US6026413?utm_source=gb-gplus-share專利 US6026413 - Determining how changes to underlying data affect cached objects
