System and method for managing versions of metadata

• US 8,005,792 B2
• Filed: 05/13/2005
• Issued: 08/23/2011
• Est. Priority Date: 05/14/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Green, Russell John, Basu, Subhransu, Hung, Ho Chak, Shankar, Shrikanth, Lee, Jaebock, Rajamani, Kumar
• Primary Examiner(s): Vital; Pierre M
• Assistant Examiner(s): Nofal; Christopher P
• Application Number:
  US11/129,717
• Publication Number:
  US 20060004886A1
• Time in Patent Office: 2,293 Days
• Field of Search: 707/1, 707/2, 707/4, 707/9, 707/100, 707/102, 707/200, 707/201, 707/203, 709/200, 709/213
• US Class Current: 707/638
• 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 computer implemented method for managing versions of metadata on a system, the method comprising:

receiving a first set of one or more first requests to operate on an object, wherein a first metadata version is associated with the object;

fulfilling the first set of one or more first requests by performing one or more first database operations associated with the one or more first requests against the object;

while the first metadata version associated with the object is being maintained for the one or more first requests, receiving a second set of one or more second requests to operate on the object, wherein a second metadata version is associated with the object,

wherein the first metadata version is obsolete and the second metadata version is not obsolete, the first metadata version and second metadata version concurrently exist for the object on the system so that the one or more first requests finish the one or more first database operations using the first metadata version while the one or more second requests uses the second metadata version;

fulfilling the second set of one or more second requests by performing one or more second database operations associated with the one or more second requests against the object;

maintaining, by using a processor, the first metadata version and the second metadata version with a dependency reference to track dependent objects accessing the first metadata version, wherein the act of maintaining comprises;

marking a state of the first metadata version to indicate a lack of the dependent objects;

deleting the first metadata version associated with the object if the state of the first metadata version is marked so that the first metadata version no longer needs to be maintained for the first set of one or more first requests to perform the one or more first database operations associated with the one or more first requests; and

storing the second metadata version in a volatile or non-volatile computer usable medium or displaying the second metadata version on a display device.

2. The computer implemented method of claim 1, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the one or more second requests is a write request;

modifying a persistent metadata version based at least in part upon the write request; and

creating a new metadata version based at least in part upon the modified persistent metadata.

3. The computer implemented method of claim 1, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the one or more second requests is a read request;

locating the second metadata version for the resource; and

determining that the second metadata version for the resource is not obsolete.

4. The computer implemented method of claim 1, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the one or more second requests is a read request; and

creating the second metadata version.

5. The computer implemented method of claim 1, further comprising:

allocating memory consumed by the second metadata version;

determining that the second metadata version is not obsolete; and

continuing to use previously allocated memory consumed by the second metadata version.

6. The computer implemented method of claim 1, further comprising:

allocating memory consumed by the second metadata version;

determining that the first metadata version has no linked dependent objects;

determining that the first metadata version is obsolete; and

releasing previously allocated memory consumed by the first metadata version.

7. The computer implemented method of claim 6, further comprising:

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

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

a processor configured for;

receiving a first set of one or more first requests to operate on an object, wherein a first metadata version is associated with the object;

fulfilling the first set of one or more first requests by performing one or more first database operations associated with the one or more first requests against the object;

while the first metadata version associated with the object is being maintained for the one or more first requests, receiving a second set of one or more second requests to operate on the object, wherein a second metadata version is associated with the object,

wherein the first metadata version is obsolete and the second metadata version is not obsolete, the first metadata version and second metadata version concurrently exist for the object on the system so that the one or more first requests finish the one or more first database operations using the first metadata version while the one or more second requests uses the second metadata version;

fulfilling the second set of one or more second requests by performing one or more second database operations associated with the one or more second requests against the object;

maintaining, by using a processor, the first metadata version and the second metadata version with a dependency reference to track dependent objects accessing the first metadata version, wherein the act of maintaining comprises;

marking a state of the first metadata version to indicate a lack of the dependent objects;

deleting the first metadata version associated with the object if the state of the first metadata version is marked so that the first metadata version no longer needs to be maintained for the first set of one or more first requests to perform the one or more first database operations associated with the one or more first requests; and

a volatile or non-volatile computer usable medium for storing the second metadata version or a display device for displaying the second metadata version.

9. The system of claim 8, wherein the processor is further configured for:

determining that at least one of the one or more second requests is a write request;

modifying a persistent metadata version based at least in part upon the write request; and

creating a new metadata version based at least in part upon the modified persistent metadata.

10. The system of claim 8, wherein the processor is further configured for:

determining that at least one of the one or more second requests is a read request;

locating the second metadata version for the resource; and

determining that the second metadata version for the resource is not obsolete.

11. The system of claim 8, wherein the processor is further configured for:

determining that at least one of the one or more second requests for the resource is a read request; and

creating the second metadata version.

12. The system of claim 8, wherein maintaining further comprises:

allocating memory consumed by the second metadata version;

determining that the second metadata version is not obsolete; and

continuing to use previously allocated memory consumed by the second metadata version.

13. The system of claim 8, wherein the processor is further configured for:

allocating memory consumed by the second metadata version;

determining that the first metadata version has no linked dependent objects;

determining that the first metadata version is obsolete; and

releasing previously allocated memory consumed by the first metadata version.

14. The system of claim 13, wherein the processor is further configured for:

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

15. A computer program product embodied on volatile or non- volatile computer usable medium, the computer usable 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 metadata on a system, the method comprising:

receiving a first set of one or more first requests to operate on an object, wherein a first metadata version is associated with the object;

fulfilling the first set of one or more first requests by performing one or more first database operations associated with the one or more first requests against the object;

while the first metadata version associated with the object is being maintained for the one or more first requests, receiving a second set of one or more second requests to operate on the object, wherein a second metadata version is associated with the object,

wherein the first metadata version is obsolete and the second metadata version is not obsolete, the first metadata version and second metadata version concurrently exist for the object on the system so that the one or more first requests finish the one or more first database operations using the first metadata version while the one or more second requests uses the second metadata version;

fulfilling the second set of one or more second requests by performing one or more second database operations associated with the one or more second requests against the object;

maintaining, by using a processor, the first metadata version and the second metadata version with a dependency reference to track dependent objects accessing the first metadata version, wherein the act of maintaining comprises;

marking a state of the first metadata version to indicate a lack of the dependent objects;

deleting the first metadata version associated with the object if the state of the first metadata version is marked so that the first metadata version no longer needs to be maintained for the first set of one or more first requests to perform the one or more first database operations associated with the one or more first requests; and

storing the second metadata version or displaying the second metadata version on a display device.

16. The computer program product of claim 15, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the second one or more requests is a write request;

modifying a persistent metadata version based at least in part upon the write request; and

creating a new metadata version based at least in part upon the modified persistent metadata.

17. The computer program product of claim 15, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the second one or more requests is a read request;

locating the second metadata version for the resource; and

determining that the second metadata version for the resource is not obsolete.

18. The computer program product of claim 15, further comprising:

linking a dependent object to the second metadata version comprises;

determining that at least one of the second one or more requests is a read request; and

creating the second metadata version.

19. The computer program product of claim 15, further comprising:

allocating memory consumed by the second metadata version;

determining that the second metadata version is not obsolete; and

continuing to use previously allocated memory consumed by the second metadata version.

20. The computer program product of claim 15, further comprising:

allocating memory consumed by the second metadata version;

determining that the first metadata version has no linked dependent objects;

determining that the first metadata version is obsolete; and

releasing previously allocated memory consumed by the first metadata version.

21. The computer program product of claim 20, the method further comprising:

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

22. A system for managing obsolete versions of metadata comprising:

storage for storing metadata versions of an object, the storage is associated with a search and create process to locate and create the metadata versions for the object; and

a processor for executing an aging-out process to maintain or release obsolete versions of metadata using a dependency reference to track dependent objects accessing the metadata versions, the aging-out process comprises;

determining if one of the metadata versions of the object has any dependent objects that are in use by marking a state of the one of the metadata versions to indicate a lack of the dependent objects; and

deleting the one of the metadata versions of the object if the dependent objects are no longer in use after completing a request to perform one or more database operations corresponding to the dependent 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 volatile or non- volatile computer usable medium, the computer usable medium having stored thereon a sequence of instructions which, when executed by a processor, causes the processor to execute a method for managing obsolete versions of metadata on a system, the method comprising:

searching and creating to locate and create metadata versions for an object;

aging-out obsolete versions of metadata using a dependency reference to track dependent objects accessing the metadata versions, the act of aging-out comprises;

determining if one of the metadata versions of the object has any dependent objects that are in use by marking a state of the one of the metadata versions to indicate a lack of the dependent objects; and

deleting the one of the metadata versions of the object if the dependent objects are no longer in use after completing a request to perform one or more database operations corresponding to the dependent object; and

storing the metadata versions or displaying the metadata versions on a display device.

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

viewing any active metadata versions.

26. A computer implemented method for managing obsolete versions of metadata on a system comprising:

searching and creating to locate and create metadata versions for an object;

aging-out obsolete versions of metadata with a dependency reference to track dependent objects accessing the metadata versions, the act of aging-out comprises;

determining if one of the metadata versions of the object has any dependent objects that are in use by marking a state of the one of the metadata versions to indicate a lack of the dependent objects; and

deleting the one of the metadata versions of the object if the dependent objects are no longer in use after completing a request to perform one or more database operations corresponding to the dependent object; and

storing the metadata versions in a volatile or non-volatile computer usable medium or displaying the metadata versions on a display device.

27. The computer implemented method of claim 26, further comprising:

viewing any active metadata versions.