DECOUPLED OBJECT IDENTIFICATION FOR OBJECT SWITCHING IN DATABASE SYSTEMS

摘要

The use of a centralized version table allows for efficient object switching . Rather than synchronizing all database agents to recognize a newly created file as containing the most recent version of a given object, database agents requiring access to t he given object need only consult the centralized version table to learn file identity information. That is, the database agents consult the centralized version table to determine which of the files associated with a given object contain the most recent version of the given object. Mechanisms associated with the use of the centralized version table also provide for efficient recovery from a failure that has occurred during an object switchi ng transaction.