Abstract: An improved system and method for reducing the size of data difference representations. The input data stream may be split into one or more output data streams such that the output data streams may be recombined and used to regenerate the original input data stream. Each of the output data streams may be independently differenced against the equivalent data stream from the previous version of the data. Non-localized changes in the input data stream may be converted into localized changes in a subset of the output data streams. The subset of output data streams no longer containing non-localized changes produce efficient (i.e., small) difference representations. The difference representations of each of these streams may be packaged into a single stream for transmission over a computer network. The receiving computer may reconstruct the multiplicity of difference representations, and recreate the multiplicity of translated data streams representing the updated data.

Abstract: A system and method for dynamically enumerating the links in arbitrary hyperlinked data structures using parsing rules are provided. A hyperlinked data structure may be enumerated by reading one or more data objects through an object access interface, parsing the one or more data objects in the data structure, identifying two or more data elements in the one or more data objects, combining one or more data elements to obtain one or more hyperlink addresses, and reading the one or more hyperlink addresses to enumerate the one or more data objects. In one embodiment, hyperlinked structures such as Websites, may be enumerated using configuration templates. The templates may include heuristic parsing rules. The definition of the templates may be independent of the evolution of the data objects over time.

Abstract: An improved system and method for reducing the size of data difference representations. The input data stream may be split into one or more output data streams such that the output data streams may be recombined and used to regenerate the original input data stream. Each of the output data streams may be independently differenced against the equivalent data stream from the previous version of the data. Non-localized changes in the input data stream may be converted into localized changes in a subset of the output data streams. The subset of output data streams no longer containing non-localized changes produce efficient (i.e., small) difference representations. The difference representations of each of these streams may be packaged into a single stream for transmission over a computer network. The receiving computer may reconstruct the multiplicity of difference representations, and recreate the multiplicity of translated data streams representing the updated data.

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.