Allowing inconsistency in a distributed client-server application

[54] ALLOWING INCONSISTENCY IN A DISTRIBUTED CLIENT-SERVER APPLICATION

[75] Inventors: Monte Zweben, San Francisco;

Michael J. Deale. Sunnyvale; Mark A.
Vershel, Palo Alto; Christophe E.
Pettus, San Francisco, all of Calif.

[73] Assignee: PeopleSoft, Inc., Pleasanton, Calif.

[21] Appl. No.: 497,506
[22] Filed: Jun. 30,1995

[51] Int CI.6 H04L 12/00

[52] U.S. CI 395/200.34; 395/200.31;

707/8

[58] Field of Search 395/200.03, 200.04,

395/200.09, 608, 610, 617, 619, 200.34, 200.31, 703; 707/8

[56] References Cited

U.S. PATENT DOCUMENTS

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OTHER PUBLICATIONS

M. Zweben et al., "Learning to improve constraint-based scheduling", Artificial Intelligence 58, Elsevier Science Publishers B.V.,1992, pp. 271-296.

M. Zweben et al., "Scheduling and Rescheduling with Iterative Repair", IEEE Transactions on Systems, Man. and Cybernetics, vol. 23, No. 6, Nov./Dec. 1993, pp. 1588-1595. M. Zweben et al., "Heuristics versus Lookahead in Iterative Repair Scheduling", The Proceedings of the 13th International Joint Conference on Artificial Intelligence, 1993, pp. 1416-1422.

M. Zweben et al., "Scheduling and Rescheduling With
Iterative Repair". Intelligent Scheduling, Chapter 8, Morgan
Kaufmann Publishers, 1994, pp. 241-255.
M. Zweben et al., "The Space Shuttle Ground Processing
Scheduling System", Intelligent Scheduling, Chapter 15,
Morgan Kaufmann Publishers, 1994, pp. 423^449.

Primary Examiner—harry D. Donaghue
Attorney, Agent, or Firm—David R. Graham

[57] ABSTRACT

The invention enables multiple users to simultaneously access and change the contents of a database in a flexible manner. Each user interacts with a working copy of a master copy of the database. The contents of each of the working copies of the database can be accessed and manipulated so that the contents of the working copy of the database can be revised. Each user has control over whether to the "publish" revisions made to the contents of that user's working copy of the database, i.e., write the revisions to the master copy and present other users with the option of including the revisions in the working copies of those other users. Each user has the option to reject revisions published by other users so that the contents of each user's working copy of the database may or may not be maintained consistent with other working copies of the database operated on by other users. However, in order to ensure data integrity of the master database, each user that rejects the inclusion of revisions published by another user is prospectively prevented from publishing revisions to other users, until the user accepts the previously rejected published revisions. The invention employs a distributed architecture that allows each user to interact with that user's working copy of the database in a way that is controlled by that user without impairing the functionality of the database for other users. The database inconsistency allowed by the invention facilitates the performance by users of "what-if' analyses.

20 Claims, 6 Drawing Sheets