Abstract: A method and apparatus are disclosed for managing a transaction log which contains updates representing operations performed on a database replica in a network of disconnectable computers. The invention provides for compression of the log by the identification and removal of redundant updates. Log compression removes apparent inconsistencies between operations performed on disconnected computers, reduces storage requirements on each computer, and speeds up transaction synchronization when the computers are reconnected. The invention also provides for restoration of prior versions of database objects using the log.

Abstract: A method and apparatus are disclosed for synchronizing transactions in a disconnectable network. Each transaction includes operations that were performed on a database replica on one computer while that computer was disconnected from another computer and hence from that other computer's replica. Transaction synchronization, which occurs after the computers are reconnected, transfers information from each computer to the other computer and applies updates to both replicas as appropriate. Transaction logs and clash handling tools may be used with the invention.

Abstract: Processes and apparatuses are provided for generating file correspondency between a source computer and a target computer. The process comprises determining a first source file key for at least a portion of the source file and searching for an existing file having at least a portion thereof represented by a first existing file key which matches the first source file key. If the first existing file key is located and if the portion of the existing file represented by the first existing file key is also disposed on the target computer, the file correspondency is generated by accessing the portion of the existing file represented by the first existing file key which is disposed on the target computer.