METHOD AND SYSTEM FOR STATE MAINTENANCE OF A LARGE OBJECT

• US 20090037495A1
• Filed: 07/30/2007
• Published: 02/05/2009
• Est. Priority Date: 07/30/2007
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Baloglu, Kaan, Kumar, Nirman, Kunchithapadam, Krishna, Muthulingam, Sujatha, Pandey, Dheeraj, Gokhale, Vipin, Baddepudi, Bharat
• Granted Patent: US 8,775,479 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2219 Large Object storage; Management thereof
• CPC Class Codes: G06F 16/24552 Database cache management

Abstract

A method, system and computer program product are described for state maintenance of a large object. In one approach, the method, system and computer program product perform by associating one or more buffers with a transaction involving a large object, the large object data may be accessed using the one or more buffers during the transaction, and storing data for the large object from the one or more buffers in one or more sets of contiguous blocks.

In one approach, a system performs state maintenance of a large object with a cache that associates one or more buffers with a transaction involving a large object, the large object data may be accessed using the one or more buffers during the transaction, and the cache stores large object data from the one or more buffers in one or more sets of contiguous blocks in storage.

Claims

1. A method for state maintenance of a large object, comprising:

associating one or more buffers with a transaction involving a large object, wherein data for the large object may be accessed using the one or more buffers during the transaction; and

storing data for the large object from the one or more buffers in one or more sets of contiguous blocks in storage.

2. The method of claim 1 for state maintenance of a large object, wherein an access of data for the large object comprises writing to the large object.

3. The method of claim 1 for state maintenance of a large object, further comprising:

associating a first snapshot of a database with the transaction involving the large object, wherein the first snapshot indicates a state of the database after a last access of the large object; and

indicating any number of transactions on the large object as being invalid in the one or more buffers for the transaction based upon the first snapshot.

4. The method of claim 3 for state maintenance of a large object, further comprising:

associating a second snapshot of the database with a last flush of the one or more buffers for the large object; and

writing data to the one or more buffers for the large object from storage using the second snapshot.

5. The method of claim 1 for state maintenance of a large object, further comprising:

compressing data in the one or more buffers before writing data for the large object to storage.

6. The method of claim 1 for state maintenance of a large object, further comprising:

comparing the large object in the one or more buffers to large objects previously written to storage; and

removing duplication of data in storage by creating a pointer to an identical large object to the large object in the one or more buffers.

7. The method of claim 1 for state maintenance of a large object, further comprising:

receiving a request to access the large object at a database management system; and

providing the one or more buffers from a database buffer cache of the database management system.

8. A computer program product comprising a computer usable medium having executable code to execute a process for implementing state maintenance for a large object in a computing system, the process comprising:

associating one or more buffers with a transaction involving a large object, wherein data for the large object may be accessed using the one or more buffers during the transaction; and

storing data for large object from the one or more buffers in one or more sets of contiguous blocks in storage.

9. The computer program product of claim 8, wherein an access of data for the large object comprises writing to the large object.

10. The computer program product of claim 8, wherein the process further comprises:

associating a first snapshot of a database with the transaction involving the large object, wherein the first snapshot indicates a state of the database after a last access of the large object; and

indicating any number of transactions on the large object as being invalid in the one or more buffers for the transaction based upon the first snapshot.

11. The computer program product of claim 10, wherein the process further comprises:

associating a second snapshot of the database with a last flush of the one or more buffers for the large object; and

writing data to the one or more buffers for the large object from storage using the second snapshot.

12. The computer program product of claim 8, wherein the process further comprises:

compressing data in the one or more buffers before writing data for the large object to storage.

13. The computer program product of claim 8, wherein the process further comprises:

comparing the large object in the one or more buffers to large objects previously written to storage; and

removing duplication of data in storage by creating a pointer to an identical large object to the large object in the one or more buffers.

14. The computer program product of claim 8, wherein the process further comprises:

receiving a request to access the large object at a database management system; and

providing the one or more buffers from a database buffer cache of the database management system.

15. A system for state maintenance of a large object, comprising:

a cache associating one or more buffers with a transaction involving a large object, wherein data for the large object may be accessed using the one or more buffers during the transaction and the cache storing data for the large object from the one or more buffers in one or more sets of contiguous blocks in storage.

16. The system of claim 15, wherein an access of data for the large object comprises writing to the large object.

17. The system of claim 15, further comprising:

the cache associating a first snapshot of a database with the transaction involving the large object, wherein the first snapshot indicates a state of the database after a last access of the large object; and

a database management system indicating any number of transactions on the large object as being invalid in the one or more buffers for the transaction based upon the first snapshot.

18. The system of claim 15, further comprising:

a mapping associating a second snapshot of the database with a last flush of the one or more buffers for the large object and the cache writing data to the one or more buffers for the large object from storage using the second snapshot.

19. The system of claim 15, further comprising:

a compression layer compressing data in the one or more buffers before writing data for the large object to storage.

20. The system of claim 15, further comprising:

a de-duplication layer comparing the large object in the one or more buffers to large objects previously written to storage and the de-duplication layer removing duplication of data in storage by creating a pointer to an identical large object to the large object in the one or more buffers.

21. The system of claim 15, further comprising:

a database management system receiving a request to access the large object and the database management system providing the one or more buffers from a database buffer cache.