Method for the dynamic replication of data under distributed system control to control utilization of resources in a multiprocessing, distributed data base system
Dynamic physical memory mapping and management of independent programming environments
Software version management system
Real-time distributed data-base management system
Method for controlling query and update processing in a database system
Database backup method
Automated query optimization method using both global and parallel local optimizations for materialization access planning for distributed databases Patent #: 4769772
ApplicationNo. 07/136174 filed on 12/18/1987
US Classes:707/203, Version management707/202Recoverability
ExaminersPrimary: Chan, Eddie P.
Assistant: Kulik, Paul V.
Attorney, Agent or Firm
International ClassG06F 17/30 (20060101)
AbstractAn object-oriented, distributed data base system separates into a plurality of virtual partitions following communication failure between sites accessing the data base. Each partition accesses a separate copy of an initial data base and independently updates groups of data objects included in the data base to add new versions of data objects to the data base. Each virtual partition maintains a copy of all previous versions of data objects and maintains a change list describing all group updates that it executes. Following restoration of communication between sites, each virtual partition merges the data bases maintained by separate partitions to form a consistent merged data base permitting versions of data objects and collections of data objects created by any one of the separate virtual partitions to be identified and accessed in the merged data base.