Methods and systems for moving data objects utilizing data identifiers and lock objects

• US 7,222,142 B2
• Filed: 09/08/2003
• Issued: 05/22/2007
• Est. Priority Date: 09/09/2002
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Fischer, Martin, Pferdekaemper, Thorsten
• Primary Examiner(s): KIM, HONG CHONG
• Application Number:
  US10/656,209
• Publication Number:
  US 20040243773A1
• Time in Patent Office: 1,352 Days
• Field of Search: 707/8, 707/10, 707/201, 707/204, 711/161, 711/162, 711/163, 711/165, 714/7, 714/6, 718/102, 710/200
• US Class Current: 707/661
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/2343 Locking methods, e.g. distributed locking or locking implementation details
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

The present invention provides methods and systems for archiving of data, that is, for moving a selected data object in a computer system from a first to a second storage location. The selected data object is assigned at least one identifier (ID) that is stored in at least one lock object. The data object is stored at the second storage location and the second storage location is associated with the ID. The data object is then deleted from the first storage location and the ID is deleted from the lock object after the storing of the data object in the second storage location has been completed. Methods and systems can check, by querying the lock object, whether the data to be accessed is subject to a moving process or not. If yes, the access to that data can be postponed until the moving is completed.

Claims

1. A method for moving a data object in a computer system from a first to a second storage location, the method comprising:

a) selecting a data object from the first storage location;

b) assigning at least one identifier (ID) to the selected data object;

c) storing the at least one ID in at least one lock object;

d) storing the selected data object at the second storage location and associating the second storage location with the at least one ID in the at least one lock object;

e) deleting the selected data object from the first storage location;

f) deleting the at least one ID from the at least one lock object after the storing of the data object in the second storage location has been completed; and

g) checking before or while performing any of steps a) to c), whether the at least one ID has been stored in the at least one lock object and, if yes, skipping at least step c).

2. The method of claim 1, wherein

the data object comprises one or more fields of one or more tables and wherein the at least one ID comprises one or more key fields of the one or more tables.

3. The method of claim 1, comprising:

storing the second storage location in the at least one lock object.

4. The method of claim 2, comprising:

storing the second storage location in the at least one lock object.

11. The method of claim 1, wherein the checking is performed by querying a lock object.

12. The method of claim 1, further comprising:

in case of a failure in step d), checking whether the data has been completely stored in the second storage location and, if the data has not been completely stored, skipping at least steps e) and f).

5. A method for moving a data object in a computer system from a first to a second storage location, the method comprising:

a) selecting a data object from the first storage location;

b) assigning a first type of ID and a second type of ID to the data object;

c) storing the first type of ID in a first lock object;

d) storing the second type of ID in a second lock object;

e) storing the data object at the second storage location and associating the second storage location with the at least the first type of ID;

f) deleting the first type of ID from the first lock object after the data object has beendeleted from the first storage location; and

g) deleting the second type of ID from the second lock object after the data object has been stored in the second storage location.

6. The method of claim 5, wherein the second type of ID is stored in the second lock object immediately after assigning IDs to the data object.

7. The method of claim 5, wherein the second type of ID is stored in the second lock object before the storing of the data object at the second storage location is started.

8. The method of claim 5, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

9. The method of claim 6, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

10. The method of claim 7, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

13. The method of claim 5, further comprising:

checking before or while performing any of steps a) to d), whether the data object is stored in the second storage location and, if yes, skipping at least step d).

14. The method of claim 13, wherein the checking is performed by querying a lock object.

15. A method for moving a data object in a computer system from a first to a second storage location, the method comprising:

a) selecting a data object having at least one identifier (ID) from the first storage location;

b) storing the at least one ID in at least one lock object;

c) storing the data object at the second storage location and associating the second storage location with the at least one ID in the at least one lock object;

d) deleting the data object from the first storage location; and

e) deleting the at least one ID from the at least one lock object after the data object has been deleted from the first storage location;

f) deleting the at least one ID from the at least one lock object after the storing of the data object in the second storage location has been completed; and

g) checking before or while performing steps a) or b), whether the at least one ID has been stored in the at least one lock object and, if yes, skipping at least step b).

16. A computer system for moving a data object from a first to a second storage location, the system comprising:

memory having program instructions;

storage means for storing data;

at least one processor to execute the program instructions to perform operations comprising;

a) selecting a data object from the first storage location;

b) assigning at least one identifier (ID) to the selected data object;

c) storing the at least one ID in at least one lock object;

d) storing the data object at the second storage location and associating the second storage location with the at least one ID in the at least one lock object;

e) deleting the data object from the first storage location;

f) deleting the at least one ID from the at least one lock object after the storing of the data object in the second storage location has been completed; and

g) checking before or while performing any of steps a) to c), whether the at least one ID has been stored in the at least one lock object and, if yes, skipping at least step c).

17. The computer system of claim 16, wherein the data object comprises one or more fields of one or more tables and wherein the at least one ID comprises one or more key fields of the one or more tables.

18. The computer system of claim 16, wherein the operations performed by the processor comprise:

storing the second storage location in the at least one lock object.

19. The computer system of claim 17, wherein the operations performed by the processor comprise storing the second storage location in the at least one lock object.

26. The computer system of claim 16, wherein the checking is performed by querying a lock object.

27. The computer system of claims 16, further comprising:

in case of a failure in step d), checking whether the data has been completely stored in the second storage location and, if the data has not been completely stored, skipping at least steps e) and f).

20. A computer system for moving a data object from a first to a second storage location, the system comprising:

memory storing program instructions;

storage means for storing data;

at least one processor to execute the program instructions to perform operations comprising;

a) selecting a data object from the first storage location;

b) assigning a first type of ID and a second type of ID to the data object;

c) storing the first type of ID in a first lock object;

d) storing the second type of ID in a second lock object;

e) storing the data object at the second storage location and associating the second storage location with the at least the first type of ID;

f) deleting the first type of ID from the first lock object after the data object has been deleted from the first storage location; and

g) deleting the second type of ID from the second lock object after the data object has been stored in the second storage location.

21. The computer system of claim 20, wherein the second type of ID is stored in the second lock object immediately after assigning IDs to the data object.

22. The computer system of claim 20, wherein the second type of ID is stored in the second lock object before the storing of the data object at the second storage location is started.

23. The computer system of claim 20, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

24. The computer system of claim 21, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

25. The computer system of claim 22, wherein the first type of ID is stored in the first lock object before the storing of the data object at the second storage location is started.

28. The computer system of claim 20, further comprising:

checking before or while performing any of steps a) to d), whether the data object is stored in the second storage location and, if yes, skipping at least step d).

29. The computer system of claim 28, wherein the checking is performed by querying a lock object.

30. A method for a moving data object in a computer system from a first to a second storage location, the method comprising:

a) selecting a data object from the first storage location;

b) assigning an identifier (ID) of a first type to the selected data object;

c) assigning an ID of a second type to the selected data object;

d) storing the first type ID in a first lock object;

e) storing the second type ID in a second lock object;

f) storing the data object at the second storage location;

g) deleting the data object from the first storage location;

h) deleting the first type ID from the first lock object after the storing of the data object in the second storage location has been completed; and

i) deleting the second type ID from the second lock object after the storing of the data object in the second storage location has been completed.

31. A computer-readable medium comprising instructions that, when executed by a processor, move data objects in a computer system from a first to a second storage location, the medium comprising instructions for:

a) selecting a data object from the first storage location;

b) assigning at least one identifier (ID) to the selected data object;

c) storing the at least one ID in at least one lock object;

d) storing the data object at the second storage location and associating the second storage location with the at least one ID in the at least one lock object;

e) deleting the data object from the first storage location;

f) deleting the at least one ID from the at least one lock object after the storing of the data object in the second storage location has been completed; and

g) checking before or while performing any of steps a) to c), whether the at least one ID has been stored in the at least one lock object and, if yes, skipping at least step c).

32. A computer-readable medium storing instructions that, when executed by a processor, move at least one data object in a computer system from a first to a second storage location, the medium storing instructions for:

a) selecting at least one data object from the first storage location;

b) assigning a first type of ID and a second type of ID to the at least one data object;

c) storing the first type of ID in a first lock object;

d) storing the second type of ID in a second lock object;

e) storing the at least one data object at the second storage location and associating the second storage location with at least the first type of ID;

f) deleting the first type of ID from the first lock object after the at least one data object has been deleted from the first storage location; and

g) deleting the second type of ID from the second lock object after the at least one data object has been stored in the second storage location.

33. A method for moving a data object in a computer system from a first to a second storage location, the method comprising:

a) selecting a data object having at least one identifier (ID) from the first storage location;

b) storing the at least one ID in a first lock object;

c) storing the at least one ID in a second lock object;

d) storing the data object at the second storage location;

e) deleting the data object from the first storage location; and

f) deleting the at least one ID from the first lock object after the data object has been stored at the second storage location; and

g) checking before or while performing steps a) or b), whether the at least one ID has been stored in the at least one lock object and, if yes, skipping at least step b).