7,103,586 - Collision avoidance in database replication systems
Abstract:Database replication systems replicate blocks of transaction steps or operations with synchronous replication, and perform dual writes with queuing and blocking of transactions. Tokens are used to prepare a target database for replication from a source database and to confirm the preparation. Database replication systems switch between a synchronous replication mode and an asynchronous replication mode, and then back to a synchronous replication mode, based on detection of selected events.