Changed data of castout classes of a coupling facility cache are managed in order to be able to efficiently determine the age of the oldest changed data in the cache. A directory entry representing a changed datum is placed in a data structure corresponding to the castout class of the changed datum....http://www.google.com.hk/patents/US6230243?utm_source=gb-gplus-share專利 US6230243 - Method, system and program products for managing changed data of castout classes
