System and method for synchronizing data in multiple databases

• US 7,222,141 B2
• Filed: 12/20/2002
• Issued: 05/22/2007
• Est. Priority Date: 12/24/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Zondervan, Quinton Yves, Lee, Alexandre J.
• Primary Examiner(s): TRUONG, CAM Y T
• Application Number:
  US10/323,835
• Publication Number:
  US 20030131025A1
• Time in Patent Office: 1,614 Days
• Field of Search: 707200-205, 711/162
• US Class Current: 1/1
• 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 records between a secondary database and a distributed database system comprising:

one or more processors;

a distributed database system comprising at least two source databases including at least one main database having a plurality of records, and at least one replica database having a subset of one or more records of the plurality of records contained in the main database, and further identifying each record within the source databases using a source database record identifier;

a secondary database including one or more records that are each record identified by a secondary database record identifier, wherein one or more of the secondary database records corresponds to a record within each source database;

an identification mapping database associated with each source database, the identification mapping database including a mapping table for associating secondary database record identifiers to corresponding source database record identifiers;

a replica identification database associated with the secondary database that contains an entry for each respective source database, each entry comprising information regarding a last synchronization between the secondary database and the respective source database including a time when the last synchronization occurred;

a delta modification database identifying and storing information including the secondary database record identifier corresponding to the one or more records of the secondary database that have been modified since the last synchronization between the secondary database and each source database according to the replica identification database, wherein the stored information for each identified record that has been modified since the last synchronization further includes an action flag that describes an action taken on the identified record; and

a synchronization module that synchronizes records that are identified by the delta modification database into corresponding records within each source database based at least in part on the mapping table and the action flag, wherein the replica identification database is updated to include the time of synchronization and the delta modification database is updated to store version numbers of said synchronized records for said synchronization.

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 delta 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 system comprise less memory than the source computer system.

5. The system of claim 4 wherein the secondary computer system 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, 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 a last synchronization between the secondary database and the source database including a version of the identification mapping database associated with the source database when the synchronization occurred.

8. The system of claim 7 further comprising a pruning module that prunes entries from the delta modification database using the replica identification database.

9. The system of claim 1, wherein the records that have been modified since a previous synchronization includes one or more of:

deleted records;

added records;

modified records.

10. The system of claim 1, wherein the stored information for each identified record that has been modified since a previous synchronization further includes:

a secondary database record identification; and

a source database record identification.

11. The system of claim 1 further comprising at least one identification database comprising a record identification number and a version number for each main database record, replica database record, and secondary database record, wherein the at least one identification database maps at least two records of the main database, the at least one replica database, and the secondary database records using the record identification numbers and the version numbers.

18. The system of claim 1, 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 means of the distributed database means, each entry comprising information regarding a last synchronization between the secondary database means and the source database including a version of the identification mapping database means associated with the source database when the synchronization occurred.

19. The system of claim 18 further comprising a pruning means for pruning entries from the delta modification database means using the replica identification database means.

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

one or more processors;

a distributed database system means comprising at least two source databases including at least one main database having a plurality of records, and at least one replica database having a subset of one or more records of the plurality of records contained in the main database, and further identifying each record within the source databases using a source database record identifier;

a secondary database means including one or more records that are each record identified by a secondary database record identifier, wherein one or more of the secondary database records corresponds to a record within each source database;

an identification mapping database means associated with each source database, the identification mapping database including a mapping table for associating secondary database record identifiers to corresponding source database record identifiers;

a replica identification database means associated with the secondary database that contains an entry for each respective source database, each entry comprising information regarding a last synchronization between the secondary database and the respective source database including a time when the last synchronization occurred;

a delta modification database means identifying and storing information including a secondary database record identifier corresponding to the one or more records of the secondary database that have been modified since the last synchronization between the secondary database and each source database according to the replica identification database, wherein the stored information for each identified record that has been modified since the last synchronization further includes an action flag that describes an action taken on the identified record; and

a synchronization means that synchronizes records that are identified by the delta modification database into corresponding records within each source database based at least in part on the mapping table and the action flag, wherein the replica identification database is updated to include the time of synchronization and the delta modification database is updated to store version numbers of said synchronized records for said synchronization means.

13. The system of claim 12 further comprising a secondary computer means connectable to the distributed database system means, wherein the secondary database means is stored on the secondary computer means.

14. The system of claim 13 wherein the delta modification database means is stored by the secondary computer means.

15. The system of claim 13 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.

16. The system of claim 15 wherein the secondary computer means comprises a palmtop electronic device.

17. The system of claim 12 wherein the secondary database and the distributed database system comprise different data storage formats.

20. The system of claim 12, wherein the records that have been modified since a previous synchronization includes one or more of:

deleted records;

added records;

modified records.

21. The system of claim 12, wherein the stored information for each identified record that has been modified since a previous synchronization further includes:

a secondary database record identification; and

a source database record identification.

22. The system of claim 12 further comprising at least one identification database comprising a record identification number and a version number for each main database record, replica database record, and secondary database record, wherein the at least one identification database maps at least two records of the main database, the at least one replica database, and the secondary database records using the record identification numbers and the version numbers.

23. A method for synchronizing data records between a secondary database and a distributed database system, comprising:

providing at least two source databases including at least one main database and at least one replica database, the at least one main database having a plurality of records, the at least one replica database having a subset of one or more records of the plurality of records contained in the at least one main database, and identifying each record within the at least two source databases by source database identifiers;

providing a secondary database including one or more records, each record identified by a secondary database record identifier, wherein one or more of the secondary database records corresponds to a record with each source database;

associating each source database with an identification mapping database, the identification mapping database includes a mapping table for associating secondary database record identifiers to corresponding source database record identifiers;

associating the secondary database with a replica identification database, the replica identification database contains an entry for each respective source database, each entry comprising information regarding a last synchronization between the secondary database and the respective source database including a time when the last synchronization occurred;

providing a delta modification database that identifies and stores information including the secondary database record identifier corresponding to the one or more records of the secondary database that have been modified since the last synchronization between the secondary database and each source database according to the replica identification database, wherein the stored information for each identified record that has been modified since the last synchronization further includes an action flag that describes an action taken on the identified record;

synchronizing records that are identified by the delta modification database into corresponding records within each source database based at least in part on the mapping table and the action flag, wherein the replica identification database is updated to include the time of synchronization; and

storing updated version numbers of said synchronized records in the delta modification database for said synchronizing.

24. The method of claim 23 further comprising the step of storing the modification database on a secondary computer system that is connectable to the distributed database system.

25. The method of claim 23 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 delta modification database.

26. The method of claim 23 further comprises 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 a last synchronization between the secondary database and the source database including a version of the identification mapping database associated with the source database when the synchronization occurred.

27. The method of claim 26 further comprising the step of pruning entries from the delta medication database using the replica identification database.

28. The method of claim 23, wherein the records that have been modified since a previous synchronization includes one or more of:

deleted records;

added records;

modified records.

29. The method of claim 23, wherein the stored information for each identified record that has been modified since a previous synchronization further includes:

a secondary database record identification; and

a source database record identification.

30. The method of claim 23 further comprising providing at least one identification database comprising a record identification number and a version number for each main database record, replica database record, and secondary database record, wherein the at least one identification database maps at least two records of the main database, the at least one replica database, and the secondary database records using the record identification numbers and the version numbers.

31. A processor readable storage medium having code embodied therein for synchronizing data records between a secondary database and a distributed database system, comprising:

providing at least two source databases including at least one main database and at least one replica database, the at least one main database having a plurality of records, the at least one replica database having a subset of one or more records of the plurality of records contained in the at least one main database, and identifying each record within the at least two source databases by source database identifiers;

providing a secondary database including one or more records, each record identified by a secondary database record identifier, wherein one or more of the secondary database records corresponds to a record with each source database;

associating each source database with an identification mapping database, the identification mapping database includes a mapping table for associating secondary database record identifiers to corresponding source database record identifiers;

associating the secondary database with a replica identification database, the replica identification database contains an entry for each respective source database, each entry comprising information regarding a last synchronization between the secondary database and the respective source database including a time when the last synchronization occurred;

providing a delta modification database that identifies and stores information including the secondary database record identifier corresponding to the one or more records of the secondary database that have been modified since the last synchronization between the secondary database and each source database according to the replica identification database, wherein the stored information for each identified record that has been modified since the last synchronization further includes an action flag that describes an action taken on the identified record;

synchronizing records that are identified by the delta modification database into corresponding records within each source database based at least in part on the mapping table and the action flag, wherein the replica identification database is updated to include the time of synchronization; and

storing updated version numbers of said synchronized records in the delta modification database for said synchronizing.

32. The medium of claim 31 further comprising code for causing the processor to store the delta modification database on a secondary computer system that is connectable to the distributed database system.

33. The medium of claim 31, 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 the 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 a last synchronization between the secondary database and the source database including a version of the identification mapping database associated with the source database when the synchronization occurred.

34. The medium of claim 31 further comprising code for causing the processor to prune entries from the delta medication database using replica identification database.

35. The medium of claim 31, wherein the records that have been modified since a previous synchronization includes one or more of:

deleted records;

added records;

modified records.

36. The medium of claim 31, wherein the stored information for each identified record that has been modified since a previous synchronization further includes:

a secondary database record identification; and

a source database record identification.

37. The medium of claim 31 further comprising code for causing the processor to access at least one identification database comprising a record identification number and a version number for each main database record, replica database record, and secondary database record, wherein the at least one identification database maps at least two records of the main database, the at least one replica database, and the secondary database records using the record identification numbers and the version numbers.