Multipoint database synchronization protocol to avoid data corruption

• US 6,393,419 B1
• Filed: 12/09/1999
• Issued: 05/21/2002
• Est. Priority Date: 02/08/1999
• Status: Expired due to Term

• Current Assignee: Optis Wireless Technology, LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Novak, Lars, Birkler, Jörgen
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): Al-Aubaidi, Haythim
• Application Number:
  US09/457,371
• Time in Patent Office: 894 Days
• Field of Search: 707/8, 707/10, 707/201, 707/204, 707/229, 710/200, 714/20
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2329 using versioning
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A database multipoint synchronization which allows multiple clients to simultaneously access and edit a database while avoiding inadvertent data corruption and ensuring the integrity of data within the database. A database manager, which may be configured as part of a database software application, keeps track of modifications saved to a database file and increments a modification change counter accordingly. When a client user accesses a database record, the database manager detects the modification change counter value. Then if that client seeks to save modifications to the database record, the database manager detects the current modification change counter value to discern whether other clients have saved modifications to the record following the access by the client presently seeking to save modifications. If the modification change counter has incremented, the client is denied authorization to save the modifications and offered a choice of alternative operations. In this way, the data within the database record is not corrupted due to inadvertently overwriting by another client'"'"'s record.

Claims

1. A multi-client database synchronization method for avoiding data corruption, the method comprising the steps of:

contacting a database manager by a first client seeking to access a database record;

allowing the first client access to the database record by the database manager;

storing a change counter value by the database manager upon the first client accessing the database record, the change counter value being a first value which corresponds to the state of the database when the first client accessed the database record;

saving a modified version of the database record having modifications made by a second client after the first client accessed the database record;

incrementing the change counter value to a value of other than the first value in response to the second client saving the modified version of the database record;

seeking to save the database record by the first client; and

denying the first client from saving the database record by the database manager upon determining the change counter value has been incremented from the first value.

2. The method of claim 1, wherein the step of allowing the first client access to the database record by the database manager comprises the database manager granting permission to the first client to access the database record.

3. The method of claim 1, wherein the step of allowing the first client access to the database record by the database manager comprises the database manager monitoring the database record to determine that the database record has been accessed.

4. The method of claim 1, wherein the step of seeking to save the database record comprises seeking permission from the database base manager by the first client to save the database record.

5. The method of claim 1, further comprising the step of:

providing alternative operations to the first client upon denying the first client from saving the database record.

6. The method of claim 5, wherein the alternative operations provided to the first client are based upon a predetermined modification authorization for the first client.

7. The method of claim 6, further comprising the step of:

selecting at least one of the alternative operations by the first client.

8. The method of claim 1, further comprising the step of:

conveying a list of alternative operations upon denying the first client from saving the database record;

wherein said alternative operations comprises one or more of the steps of;

updating the database record to reflect any modifications previously saved by a second client;

saving the database record under a new file name;

seeking permission from the second client by the first client to save the at least a portion of the database record;

copying and pasting modifications of the database record, if any, to a clipboard;

reviewing the second client'"'"'s modifications, if any, by the first client before the first client saves the database record;

or

saving the database record over a corresponding database record previously saved by a second client.

9. A multi-client database synchronization method for avoiding data corruption of the data within the database or data to be added to the database, the method comprising the steps of:

accessing a database record by a first client;

storing a change counter value upon the first client accessing to the database record, the change counter value having a first value for the database record corresponding to the state of the database when the first client accessed the database record;

creating a modified version of the database record with modifications by a second client after the first client accessed the database record; and

notifying the first client of the modifications to the database record.

10. The method of claim 9, further comprising the step of:

providing alternative operations to the first client upon denying the first client from saving the database record.

11. The method of claim 10, wherein the alternative operations provided to the first client are based upon a predetermined modification authorization for the first client.

12. The method of claim 11, further comprising the step of:

selecting at least one of the alternative operations by the first client.

13. The method of claim 9, wherein the step of notifying the first client is performed in response to the second client saving the modified version of the database.

14. The method of claim 9, wherein the step of notifying the first client is performed in response to the second client creating the modified version of the database.