Application-specific conflict resolution for weakly consistent replicated databases

• US 5,603,026 A
• Filed: 12/07/1994
• Issued: 02/11/1997
• Est. Priority Date: 12/07/1994
• Status: Expired due to Term

• Current Assignee: Yoranso Consulting LLC (Intellectual Ventures LLC)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Petersen, Karin, Terry, Douglas B., Theimer, Marvin M., Spreitzer, Michael J., Welch, Brent B., Demers, Alan J.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Alam, Hosain T.
• Application Number:
  US08/352,014
• Time in Patent Office: 797 Days
• Field of Search: 395/325, 395/425, 395/600, 395/650, 395/575, 395/700, 395/725, 395/800, 395/153-161, 395/200.03, 395/200.13
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2329 using versioning
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

Write operations for weakly consistent replicated database systems have embedded application-specific merge procedures that are invoked for resolving conflicts whenever it is found that the related write operation conflicts with the current state of a given instance of such a database. The effect of executing such a merge procedure is deterministic for any state of the given instance of the database happens to be in when the merge procedure is executed.

Claims

1. For a distributed database system, an application-specific process for resolving conflicts that are found to exist between an instance of a database and any write operations that are presented for updating said instance of said database, said process comprising

associating an arbitrary merge-procedure, specified by said application, with each of said write operations, where the effect of executing the merge-procedure is deterministic for any given state of said instance of said database at any time that said merge-procedure is executed;

and

executing the merge-procedure associated with a given write operation whenever it is found that the given write operation conflicts with said instance of said database, said merge-procedure producing a deterministic set of updates that are applied to said database in lieu of any updates originally contemplated by the given write operation.