Storage model for large object columns

• US 20060075006A1
• Filed: 09/23/2004
• Published: 04/06/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Yu, Qin, Kotsovolos, Susan, Krishnaprasad, Muralidhar, Chang, Thomas, Muralidhar, Subramanian
• Granted Patent: US 7,853,619 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 16/289 Object oriented databases

Abstract

Methods and apparatus for enabling a plurality of table columns arranged to be associated with large objects (LOBs) to share a single LOB data segment within a database are disclosed. According to one aspect of the present invention, a method for allocating space associated with at least a first column arranged to accommodate LOB data and a second column arranged to accommodate LOB data includes allocating a first LOB data segment. The method also includes associating both the first column and the second column with the first LOB data segment.

Claims

1. A method for allocating space associated with at least one table of a computing system, the at least one table having at least a first column arranged to accommodate large object (LOB) data and a second column arranged to accommodate LOB data, the at least one table being arranged within a database, the method comprising:

allocating a first LOB data segment associated with the at least one table, wherein the first LOB data segment is arranged within the database;

associating the first column with the first LOB data segment; and

associating the second column with the first LOB data segment.

2. The method of claim 1 wherein associating the first column with the first LOB data segment includes causing a LOB associated with the first column to be arranged to be stored in the first LOB data segment.

3. The method of claim 1 wherein associating the second column with the first LOB data segment includes causing a LOB associated with the second column to be arranged to be stored in the first LOB data segment.

4. The method of claim 1 wherein the at least one table includes a first table, and the first column and the second column are included in the first table.

5. The method of claim 1 wherein the at least one table includes a first table and a second table, and the first column is a part of the first table and the second column is a part of the second table.

6. The method of claim 1 wherein the first column is associated with a first partition of the at least one table and the second column is associated with a second partition of the at least one table.

7. A computer program product for allocating space associated with at least one table of a computing system, the at least one table having at least a first column arranged to accommodate large object (LOB) data and a second column arranged to accommodate LOB data, the at least one table being arranged within a database, the computer program product comprising:

computer code that causes a first LOB data segment associated with the at least one table to be allocated, wherein the first LOB data segment is arranged within the database;

computer code that causes the first column to be associated with the first LOB data segment;

computer code that causes the second column to be associated with the first LOB data segment; and

a computer-readable medium that stores the computer codes.

8. The computer program product of claim 7 wherein the computer code that causes the first column to be associated with the first LOB data segment includes computer code that causes LOB associated with the first column to be arranged to be stored in the first LOB data segment.

9. The computer program product of claim 7 wherein the computer code that causes the second column to be associated with the first LOB data segment includes computer code that causes a LOB associated with the second column to be arranged to be stored in the first LOB data segment.

10. The computer program product of claim 7 wherein the at least one table includes a first table, and the first column and the second column are included in the first table.

11. The computer program product of claim 7 wherein the at least one table includes a first table and a second table, and the first column is a part of rhw first table and the second column is a part of the second table.

12. A database suitable for use in a computing system, the database comprising:

at least one table, the at least one table having a first large object (LOB) column and a second LOB column; and

a first LOB data segment, the first LOB data segment being arranged to store data associated with the at least one table, the first LOB data segment being mapped to both the first LOB column and to the second LOB column.

13. The database of claim 12 wherein the data has a size that is greater than a threshold amount.

14. The database of claim 13 wherein the threshold amount is user-configurable.

15. The database of claim 13 wherein the threshold amount is system-defined.

16. The database of claim 12 wherein data associated with the first LOB column is stored in-line in the first LOB column when the data has a size that is less than a threshold amount.

17. The database of claim 12 wherein the data is stored as a LOB in the first LOB data segment.

18. The database of claim 12 wherein the at least one table includes a first table, and the first LOB column and the second LOB column are each associated with the first table.

19. The database of claim 12 wherein the at least one table includes a first table and a second table, the first LOB column being associated with the first table and the second LOB column being associated with the second table.

20. The database of claim 12 wherein, the first LOB column is associated with a first partition of the at least one table and the second LOB column is associated with a second partition of the at least one table.

21. The database of claim 12 wherein the first LOB data segment includes a first LOB associated with the first LOB column and a second LOB associated with the second LOB column.

22. A method for storing data associated with at least a first column arranged to accommodate large object (LOB) data and a second column arranged to accommodate LOB data, the first column and the second column each being associated with a shared LOB data segment, the first column, the second column, and the shared LOB data segment being arranged within a database, the method comprising:

receiving a first set of data to be stored, the first set of data being associated with the first column;

determining when the first set of data is of a size that exceeds a threshold;

storing the first set of data in the shared LOB data segment when it is determined that the first set of data is of the size that exceeds the threshold; and

storing the first set of data in-line in the first column when it is determined that the first set of data is not of the size that exceeds the threshold.

23. The method of claim 22 wherein storing the first set of data in the shared LOB data segment includes storing an indicator in the first column that is arranged to identify the first set of data.

24. The method of claim 22 wherein storing the first set of data in the shared LOB data segment includes storing the first set of data in a LOB in the shared LOB data segment.

25. The method of claim 22 further including:

receiving a second set of data to be stored, the second set of data being associated with the second column;

determining when the second set of data is of a size that exceeds the threshold;

storing the second set of data in the shared LOB data segment when it is determined that the second set of data is of the size that exceeds the threshold; and

storing the second set of data in-line in the second column when it is determined that the second set of data is not of the size that exceeds the threshold.

26. The method of claim 22 wherein the first column and the second column are part of a first table.

27. A computer program product for storing data associated at least a first column arranged to accommodate large object (LOB) data and a second column arranged to accommodate LOB data, the first column and the second column each being associated with a shared LOB data segment, the first column, the second column, and the shared LOB data segment being arranged within a database, the computer program product comprising:

code devices that cause a first set of data to be stored to be received, the first set of data being associated with the first column;

code devices that cause a determination of when the first set of data is of a size that exceeds a threshold;

code devices that cause the first set of data to be stored in the shared LOB data segment when it is determined that the first set of data is of the size that exceeds the threshold;

code devices that cause the first set of data to be stored in-line in the first column when it is determined that the first set of data is not of the size that exceeds the threshold; and

a computer-readable medium that stores the code devices.

28. The computer program product of claim 27 wherein the code devices that cause the first set of data to be stored in the shared LOB data segment include code devices that cause an indicator to be stored in the first column that is arranged to identify the first set of data.

29. The computer program product of claim 27 wherein the code devices that cause the first set of data to be stored in the shared LOB data segment include code devices that cause the first set of data to be stored in a LOB in the shared LOB data segment.

30. The computer program product of claim 27 further including:

code devices that cause a second set of data to be stored to be received, the second set of data being associated with the second column;

code devices that cause a determination of when the second set of data is of a size that exceeds the threshold;

code devices that cause the second set of data to be stored in the shared LOB data segment when it is determined that the second set of data is of the size that exceeds the threshold; and

code devices that cause the second set of data to be stored in-line in the second column when it is determined that the second set of data is not of the size that exceeds the threshold.

31. A computing system comprising:

a database, the database including at a first table column arranged to be associated with large object (LOB) data and a second table column arranged to be associated with LOB data, the database further including a first LOB data segment;

means for allocating the first LOB data segment to both the first table column and the second table column;

means for storing a LOB associated with the first table column in the first LOB data segment; and

means for storing a LOB associated with the second table column in the first LOB data segment.

32. The computing system of claim 31 wherein the first table column and the second table column are a part of a first table.

33. A method for allocating space associated with at least one table of a computing system, the at least one table having at least a first column arranged to accommodate data and a second column arranged to accommodate data, the at least one table being arranged within a database, the method comprising:

allocating a first data segment associated with the at least one table, wherein the first data segment is arranged within the database;

associating the first column with the first data segment; and

associating the second column with the first data segment.

34. The method of claim 33 wherein associating the first column with the first data segment includes causing data associated with the first column to be arranged to be stored in the first data segment.

35. The method of claim 33 wherein associating the second column with the first data segment includes causing data associated with the second column to be arranged to be stored in the first data segment.

36. The method of claim 33 wherein the at least one table includes a first table, and the first column and the second column are included in the first table.

37. The method of claim 33 wherein the at least one table includes a first table and a second table, and the first column is a part of the first table and the second column is a part of the second table.

38. The method of claim 33 wherein the first column is associated with a first partition of the at least one table and the second column is associated with a second partition of the at least one table.