System and method for synchronizing data in multiple databases

• US 20030131025A1
• Filed: 12/20/2002
• Published: 07/10/2003
• Est. Priority Date: 12/24/1998
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Zondervan, Quinton Yves, Lee, Alexandre J.
• Granted Patent: US 7,222,141 B2
• Time in Patent Office: Days
• US Class Current: 707/200
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A system, method, and processor readable medium containing code for causing a processor to synchronize a secondary database system, such as one stored on a palmtop electronic device, with a distributed database system, comprising a main database and at least one replica database. The system further comprises a modification module that contains entries for modifications that have been made to the secondary database since a previous synchronization between the secondary database and the distributed database system and a synchronization module that synchronizes the secondary database with one of the databases of the distributed database system using the modification module. Each database in the distributed database system stores an identification mapping database having an assigned version number. The system further comprises a replica identification database associated with the secondary database that contains an entry for each source database of the distributed database system, each entry comprising information regarding the last synchronization between the secondary database and the source database including the version of the identification mapping database associated with the source database when the synchronization occurred. A pruning module is provided for pruning entries from the modification module using the replication identification database.

Claims

1. A system for synchronizing data between a secondary database and a distributed database system comprising:

a distributed database system comprising at least two source databases including a main database and at least one replica database;

a secondary database;

a modification database that contains entries for modifications that have been made to the secondary database since a previous synchronization between the secondary database and the distributed database system; and

a synchronization module that synchronizes the secondary database with one of the databases of the distributed database system using the modification database.

2. The system of claim 1 further comprising a secondary computer system connectable to the distributed database system, wherein the secondary database is stored on the secondary computer system.

3. The system of claim 2 wherein the modification database is stored by the secondary computer system.

4. The system of claim 2 further comprising a source computer system connected to the distributed database system and wherein the secondary computer comprises less memory than the source computer system.

5. The system of claim 4 wherein the secondary computer is a palmtop electronic device.

6. The system of claim 1 wherein the secondary database and the distributed database system comprise different data storage formats.

7. The system of claim 1 further comprising one or more identification mapping databases containing entries corresponding a record of the secondary database with a record of the distributed database system;

and

wherein the synchronization module utilizes the identification mapping database during synchronization if information used by the synchronization module is not contained in the modification database.

8. The system of claim 1 wherein each database in the distributed database system has associated therewith an identification mapping database, the identification mapping database having a version number assigned by the system;

and

further comprising a replica identification database associated with the secondary database that contains an entry for each source database of the distributed database system, each entry comprising information regarding the last synchronization between the secondary database and the source database including the version of the identification mapping database associated with the source database when the synchronization occurred.

9. The system of claim 8 further comprising a pruning module that prunes entries from the modification database using the replication identification database.

10. A system for synchronizing data between a secondary database and a distributed database system comprising:

distributed database means including a main database and at least one replica database;

secondary database means;

modification database means that contains entries for modifications that have been made to the secondary database since a previous synchronization between the secondary database and the distributed database system; and

synchronization means for synchronizes the secondary database means with one of the databases of the distributed database means using the modification database means.

11. The system of claim 10 further comprising a secondary computer means connectable to the distributed database means, wherein the secondary database means is stored on the secondary computer means.

12. The system of claim 11 wherein the modification database means is stored by the secondary computer means.

13. The system of claim 11 further comprising a source computer means connected to the distributed database means and wherein the secondary computer means comprises less memory than the source computer means.

14. The system of claim 13 wherein the secondary computer means comprises a palmtop electronic device.

15. The system of claim 10 wherein the secondary database and the distributed database system comprise different data storage formats.

16. The system of claim 10 further comprising one or more identification mapping database means containing entries corresponding a record of the secondary database means with a record of the distributed database means;

and

wherein the synchronization means utilizes the identification mapping database during synchronization if information used by the synchronization means is not contained in the modification database means.

17. The system of claim 10 wherein each database in the distributed database means has associated therewith an identification mapping database means, the identification mapping database means having a version number assigned by the system;

and

further comprising a replica identification database means associated with the secondary database means that contains an entry for each source database of the distributed database means, each entry comprising information regarding the last synchronization between the secondary database means and the source database including the version of the identification mapping database means associated with the source database when the synchronization occurred.

18. The system of claim 17 further comprising a pruning means for pruning entries from the modification database means using the replication identification database means.

19. A method for synchronizing data between a secondary database and a distributed database system, the distributed database comprising at least two source databases including a main database and at least one replica database, the method comprising the steps of:

providing a modification database that contains entries for modifications that have been made to the secondary database since a previous synchronization between the secondary database and the distributed database system; and

utilizing the modification database to synchronize the secondary database with one of the databases of the distributed database system.

20. The method of claim 19 further comprising the step of storing the modification database on a secondary computer system that is connectable to the distributed database system.

21. The method of claim 19 further comprising the step of providing one or more identification mapping databases containing entries corresponding a record of the secondary database with a record of the distributed database system;

and

using the identification mapping database if information is not contained in the modification database.

22. The method of claim 19 further comprising the steps of:

providing an identification mapping database containing entries corresponding a record of the secondary database with a record of the distributed database system, the identification mapping database having a version number assigned by the system; and

providing a replica identification database associated with the secondary database that contains an entry for each source database of the distributed database system, each entry comprising information regarding the last synchronization between the secondary database and the source database including the version of the identification mapping database associated with the source database when the synchronization occurred.

23. The method of claim 22 further comprising the step of pruning entries from the modification database using the replication identification database.

24. A processor readable medium having code embodied therein for synchronizing data between a secondary database and a distributed database system, the distributed database comprising at least two source databases including a main database and at least one replica database, the medium comprising:

code for causing a processor to access a modification database that contains entries for modifications that have been made to the secondary database since a previous synchronization between the secondary database and the distributed database system; and

code for causing a processor to utilize the modification database to synchronize the secondary database with one of the databases of the distributed database system.

25. The medium of claim 24 further comprising code for causing a processor to store the modification database on a secondary computer system that is connectable to the distributed database system.

26. The medium of claim 24 further comprising:

code for causing a processor to provide one or more identification mapping databases containing entries corresponding a record of the secondary database with a record of the distributed database system; and

code for causing a processor to use the identification mapping database if information is not contained in the modification database.

27. The medium of claim 24 further comprising code for causing a processor to provide an identification mapping database containing entries corresponding a record of the secondary database with a record of the distributed database system, the identification mapping database having a version number assigned by the system;

and

code for causing a processor to provide a replica identification database associated with the secondary database that contains an entry for each source database of the distributed database system, each entry comprising information regarding the last synchronization between the secondary database and that source database including the version of the identification mapping database associated with the source database when the synchronization occurred.

28. The medium of claim 24 further comprising code for causing a processor to prune entries from the modification database using the replication identification database.