A key problem in using caching technology for dynamic contents
lies in update management. An update management scheme should
be very efficient without imposing much extra burden to the system, especially
to the original database server. We propose an scalable update
management mechanism for query result caching in database-backed
Web sites. Our mechanism employs a two-phase consistency checking
method, which prunes out unaffected queries at the earliest possible moment.
The method scales well with a high number of cached instances.