System for managing versions of cached metadata

• US 20060004886A1
• Filed: 05/13/2005
• Published: 01/05/2006
• Est. Priority Date: 05/14/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Shankar, Shrikanth, Lee, Jaebock, Green, Russell John, Basu, Subhransu, Hung, Ho Chak, Rajamani, Kuma
• Granted Patent: US 8,005,792 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2329 using versioning

Abstract

Versioned metadata allows multiple versions of metadata for a given object to exist concurrently on a system thereby supporting the parallel execution of operations which would otherwise be mutually exclusive. Metadata updates are permitted while other objects maintain access to another version of the metadata through a versioning infrastructure. The versioning infrastructure allows the creation of new versions of metadata, maintains obsolete versions in the system as long as they are being used by any object, and deletes the obsolete versions once they are no longer in use.

Claims

1. A method for managing versions of metadata, the method comprising:

linking a dependent object to a most recent metadata version of the resource, the resource being specified in a request;

maintaining any metadata versions while in use; and

deleting any metadata versions when no longer in use.

2. The method of claim 1, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a write request;

modifying a persistent metadata version based on the request;

creating a new metadata version based on the modified persistent metadata; and

linking the dependent object to the new metadata version.

3. The method of claim 1, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a read request;

locating the most recent metadata version for the resource;

determining that the most recent metadata version for the resource is not obsolete;

linking the dependent object to the metadata version.

4. The method of claim 1, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a read request;

locating the most recent metadata version for the resource;

determining that the most recent metadata version for the resource is obsolete;

creating a new metadata version; and

linking the dependent object to the new metadata version.

5. The method of claim 1, wherein maintaining any metadata versions comprises:

determining that the metadata version is not obsolete;

or

determining that the metadata version has at least one linked dependent object; and

continuing to use the memory consumed by the metadata version.

6. The method of claim 1, wherein deleting any metadata version comprises:

determining that the metadata has no linked dependent objects;

determining that the metadata version is obsolete; and

releasing the memory consumed by the metadata version.

7. The method of claim 6, wherein deleting any metadata version further comprises:

marking a state of the metadata to indicate the lack of linked dependent objects.

8. A system for managing versions of metadata, the method comprising:

means for linking a dependent object to a most recent metadata version of the resource, the resource being specified in a request;

means for maintaining any metadata versions while in use; and

means for deleting any metadata versions when no longer in use.

9. The system of claim 8, wherein linking the dependent object to the most recent metadata version comprises:

means for determining that the request for the resource is a write request;

means for modifying a persistent metadata version based on the request;

means for creating a new metadata version based on the modified persistent metadata; and

means for linking the dependent object to the new metadata version.

10. The system of claim 8, wherein linking the dependent object to the most recent metadata version comprises:

means for determining that the request for the resource is a read request;

means for locating the most recent metadata version for the resource;

means for determining that the most recent metadata version for the resource is not obsolete;

means for linking the dependent object to the metadata version.

11. The system of claim 8, wherein linking the dependent object to the most recent metadata version comprises:

means for determining that the request for the resource is a read request;

means for locating the most recent metadata version for the resource;

means for determining that the most recent metadata version for the resource is obsolete;

means for creating a new metadata version; and

means for linking the dependent object to the new metadata version.

12. The system of claim 8, wherein maintaining any metadata versions comprises:

means for determining that the metadata version is not obsolete;

or

means for determining that the metadata version has at least one linked dependent object; and

means for continuing to use the memory consumed by the metadata version.

13. The system of claim 8, wherein deleting any metadata version comprises:

means for determining that the metadata has no linked dependent objects;

means for determining that the metadata version is obsolete; and

means for releasing the memory consumed by the metadata version.

14. The system of claim 13, wherein deleting any metadata version further comprises:

means for marking a state of the metadata to indicate the lack of linked dependent objects.

15. A computer program product embodied on computer readable medium, the computer readable medium having stored thereon a sequence of instructions which, when executed by a processor, causes the processor to execute a method for managing versions of data, the method comprising:

linking a dependent object to a most recent metadata version of the resource, the resource being specified in a request;

maintaining any metadata versions while in use; and

deleting any metadata versions when no longer in use.

16. The computer program product of claim 15, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a write request;

modifying a persistent metadata version based on the request;

creating a new metadata version based on the modified persistent metadata; and

linking the dependent object to the new metadata version.

17. The computer program product of claim 15, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a read request;

locating the most recent metadata version for the resource;

determining that the most recent metadata version for the resource is not obsolete;

linking the dependent object to the metadata version.

18. The computer program product of claim 15, wherein linking the dependent object to the most recent metadata version comprises:

determining that the request for the resource is a read request;

locating the most recent metadata version for the resource;

determining that the most recent metadata version for the resource is obsolete;

creating a new metadata version; and

linking the dependent object to the new metadata version.

19. The computer program product of claim 15, wherein maintaining any metadata versions comprises:

determining that the metadata version is not obsolete;

or

determining that the metadata version has at least one linked dependent object; and

continuing to use the memory consumed by the metadata version.

20. The computer program product of claim 15, wherein deleting any metadata version comprises:

determining that the metadata has no linked dependent objects;

determining that the metadata version is obsolete; and

releasing the memory consumed by the metadata version.

21. The computer program product of claim 20, wherein deleting any metadata version further comprises:

marking a state of the metadata to indicate the lack of linked dependent objects.

22. A system for managing versions of metadata comprising:

a search and create process to locate and create metadata versions;

an aging-out process to maintain or release obsolete versions of metadata; and

a dependency mechanism, to allow an object to declare dependency on a metadata object.

23. The system of claim 22, further comprising a viewing module to view any active metadata versions.

24. A computer program product embodied on computer readable medium, the computer readable medium having stored thereon a sequence of instructions which, when executed by a processor, causes the processor to execute a method for managing versions of data, the method comprising:

searching and creating to locate and create metadata versions;

aging-out obsolete versions of metadata; and

creating dependencies to allow an object to declare dependency on a metadata object.

25. The computer program product of claim 24, further comprising:

viewing any active metadata versions.

26. A method for managing versions of metadata comprising:

searching and creating to locate and create metadata versions;

aging-out obsolete versions of metadata; and

creating dependencies to allow an object to declare dependency on a metadata object.

27. The method of claim 26, further comprising:

viewing any active metadata versions.