Remote log based replication solution

• US 6,622,152 B1
• Filed: 05/09/2000
• Issued: 09/16/2003
• Est. Priority Date: 05/09/2000
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chia, Kenneth S., Sinn, Richard Pong Nam
• Primary Examiner(s): Robinson, Greta
• Assistant Examiner(s): RAYYAN, SUSAN F
• Application Number:
  US09/567,958
• Time in Patent Office: 1,225 Days
• Field of Search: 707/103, 707/201, 707/202-204, 707/10, 707/8, 707/200
• US Class Current: 707/637
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 16/284 Relational databases
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A method, apparatus and program storage device for optimizing a relational database management system is provided. The method employs a replication solution wherein both Apply and Capture utilities are co-located on the target system. Changes detected by the Capture utility are entered in an internal staging area on the target system. The method allows the transformed database management system to perform more efficiently than the original system, while providing the same results.

Claims

1. A method for database replication, the method comprising:

at a single site, performing the steps of;

capturing a base table change from a remote journal located on the single site, the remote journal receiving and storing entries from a local journal located on a source site;

putting said base table change into a staging area; and

retrieving said base table change from said staging area and applying said change to a target table, the target table being located on the single site.

2. The method according to claim 1, wherein said capture is accomplished by a capture component and said retrieving and applying are accomplished by an apply component.

3. The method according to claim 1, wherein said single site is said target site.

4. The method according to claim 1, wherein said base table is located on a first system and said change is stored in a journal.

5. The method according to claim 4, wherein said journal is a remote journal, the remote journal residing on a system remote to said first system.

6. The method according to claim 1, wherein said staging area comprises a change data table and a unit of work table.

7. The method according to claim 1, wherein said staging area is located on said target site.

8. The method according to claim 1, wherein said journal is a local journal, the local journal located on said first system.

9. The method according to claim 8, further comprising:

at least a remote journal, the remote journal located on at least one target system; and

said remote journal receiving entries from said local journal.

10. An apparatus for performing optimized database replication, the performance comprising:

at a single site, performing the steps of;

capturing a base table change from a remote journal located on the single site, the remote journal receiving and storing entries from a local journal located on a source site;

putting said base table change into a staging area; and

retrieving said base table change from said staging area and applying said change to a target table, the target table being located on the single site.

11. An apparatus for performing optimized database replication, the apparatus comprising:

a computer having a first electronic storage device coupled thereto for storing a source database, a replication being performed by said computer to replicate data from said source database;

an operational system having a second electronic storage device coupled thereto for storing a target database;

said target database having at least a base table and at least a local journal;

said target database comprising a target table and said operational system being a target system;

at least a remote journal for receiving and storing entries from said local journal, said remote journal located on said target system;

at least a capture utility for capturing changes to said base table from said remote journal and transferring said changes to a staging area;

at least an apply utility for retrieving said changes from said staging area and applying said changes to said target table; and

said capture utility located on said target system and said apply utility located on said target system.

12. The apparatus of claim 11, wherein said staging area comprises a unit of work table and a change of data table.

13. A program storage device readable by a computer and tangibly embodying a program of instructions executable by the computer to perform a method for remote log based database replication, the replication being performed by the computer to replicate data from a database stored in an electronic storage device coupled to the computer, the method comprising:

at a single site, performing the steps of;

capturing a base table change from a remote journal located on the single site, the remote journal receiving and storing entries from a local journal located on a source site;

putting said base table change into a staging area; and

retrieving said base table change from said staging area and applying said change to a target table, the target table being located on the single site.

14. The program storage device according to claim 13, wherein said capture is accomplished by a capture component and said retrieving and applying are accomplished by an apply component.

15. The program storage device according to claim 13, wherein said single site is said target site.

16. The program storage device according to claim 13, wherein said journal is a remote journal.

17. The program storage device according to claim 13, wherein said staging area comprises a change data table and a unit of work table.

18. The program storage device according to claim 13, wherein said staging area is located on said target site.

19. The program storage device according to claim 13, wherein said journal is a local journal, the local journal existing on said electronic storage device.

21. The method according to claim 13, wherein said base table is located on a first system and said change is stored in a journal.

20. A method for database replication, the method comprising:

initializing a capture of a base table change to a base table located on a source site with a capture utility located on a target site, said change being captured from a remote journal located on the target site, the remote journal receiving and storing entries from a local journal located on the source site;

transferring said base table change from said capture utility to an apply utility and applying said change to a target table, the target table being located on the target site;

said capture being accomplished by a capture component and said retrieving and applying being accomplished by an apply component; and

said capture component and said apply component co-existing on the target site.

22. An optimized database replication device comprising:

a computer usable medium having computer readable program code means embodied therein for causing optimized database replication, the computer readable program code means in the optimized database replication device comprising;

computer readable code means for causing a computer having a first electronic storage device coupled thereto for storing a source database to replicate data from said source database;

computer readable code means for causing a computer having an operational system having a second electronic storage device coupled thereto to store a target database;

computer readable code means for causing a computer with said target database to have at least a base table and at least a local journal;

computer readable code means for causing a computer with said target database to generate a target table and said operational system being a target system;

computer readable code means for causing a computer to generate at least a remote journal for receiving and storing entries from said local journal, said remote journal located on said target system;

computer readable code means for causing a computer to generate at least a capture utility for capturing changes to said base table from said remote journal and transferring said changes to a staging area;

computer readable code means for causing a computer to generate at least an apply utility for retrieving said changes from said staging area and applying said changes to said target table; and

computer readable code means for causing a computer to position said capture utility on said target system and position said apply utility on said target system.

23. The optimized database replication device according to claim 22, wherein said staging area comprises a unit of work table and a change of data table.

24. The optimized database replication device according to claim 22, wherein said staging area is located on said target site.

25. A method for performing optimized database replication comprising:

replicating data from a source database stored on a first electronic storage device coupled to a computer;

storing a target database on a second electronic storage device operably connected to an operational system, said target database having at least a base table and at least a local journal, said target database comprising a target table and said operational system being a target system;

receiving and storing entries from said journal on at least a remote journal located on said target system;

capturing changes to said base table from said remote journal and transferring said changes to a staging area with at least a capture utility; and

retrieving said changes from said staging area and applying said changes to said target table with at least an apply utility, said capture utility located on said target system and said apply utility located on said target system.

26. The method according to claim 25, wherein said staging area comprises a unit of work table and a change of data table.

27. The method according to claim 25, wherein said staging area is located on said target site.