METHOD OF MANAGING CACHE MEMORY BASED ON DATA TEMPERATURE

• US 20070067575A1
• Filed: 09/07/2006
• Published: 03/22/2007
• Est. Priority Date: 09/20/2005
• Status: Abandoned Application

• Current Assignee: Teradata US, Inc. (Teradata Corporation)
• Original Assignee: Teradata US, Inc. (Teradata Corporation)
• Inventors: Ramesh, Bhashyam, Morris, John
• Application Number:
  US11/470,710
• Publication Number:
  US 20070067575A1
• Time in Patent Office: Days
• US Class Current: 711/133
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/0888 using selective caching, e.g. bypass
• CPC Class Codes: G06F 12/121 using replacement algorithms

Abstract

A technique for use in managing a data cache involves receiving one or more data objects to be written to a storage device. A temperature value is assigned to the one or more data objects before storing the data objects in the data cache. The temperature value assigned to the one or more data objects is compared with a threshold value. A copy of the one or more data objects is stored in the data cache if the assigned temperature value exceeds the threshold value.

Claims

1. A method of managing a data cache, the method comprising:

receiving one or more data objects to be written to a storage device;

assigning a temperature value to the one or more data objects;

comparing the temperature value assigned to the one or more data objects with a threshold value; and

storing a copy of the one or more data objects in the data cache if the assigned temperature value exceeds the threshold value.

2. The method of claim 1 wherein the step of assigning a temperature value to the one or more data objects includes the steps of:

obtaining from a user a user specified temperature value; and

assigning the user specified temperature value to the one or more data objects.

3. The method of claim 1 wherein the step of assigning a temperature value to the one or more data objects includes the steps of:

calculating a system specified temperature value; and

assigning the system specified temperature value to the one or more data objects.

4. The method of claim 3 wherein the step of calculating a system specified temperature value is based at least partly on a data object type associated with the one or more data objects.

5. The method of claim 1 wherein the temperature value is selected from an ordered set of temperature values.

6. The method of claim 5 wherein the threshold value is selected from the ordered set of temperature values.

7. The method of claim 1 wherein the temperature value is a numerical value.

8. The method of claim 7 wherein the threshold value is a numerical value.

9. A method of managing a data cache, the method comprising:

receiving one or more data objects to be written to a storage device, the data object(s) associated with respective temperature values;

comparing the temperature value associated with one or more data objects with a threshold value; and

storing a copy of the one or more data objects in the data cache if the assigned temperature value exceeds the threshold value.

10. The method of claim 9 wherein the temperature value has been specified by a user.

11. The method of claim 9 wherein the temperature value has been calculated by an automated process.

12. The method of claim 9 wherein the temperature value has been selected from an ordered set of temperature values.

13. The method of claim 12 wherein the threshold value has been selected from the ordered set of temperature values.

14. The method of claim 9 wherein the temperature value is a numerical value.

15. The method of claim 14 wherein the threshold value is a numerical value.

16. A method of managing a data cache associated with a plurality of data objects written to a storage device, the method comprising:

maintaining respective temperature values for one or more of the plurality of data objects;

comparing the temperature value(s) associated with the one or more data objects with a threshold value; and

deleting one or more data objects from the data cache if the associated temperature value is lower than the threshold value.

17. The method of claim 16 further including the step of increasing the threshold value if no data objects in the data cache have an associated temperature value lower than the threshold value.

18. The method of claim 16 wherein the temperature value has been specified by a user.

19. The method of claim 16 wherein the temperature value has been calculated by an automated process.

20. The method of claim 16 wherein the temperature value has been selected from an ordered set of temperature values.

21. The method of claim 20 wherein the threshold value has been selected from the ordered set of temperature values.

22. The method of claim 16 wherein the temperature value is a numerical value.

23. The method of claim 22 wherein the threshold value is a numerical value.

24. A method of managing a data cache associated with a plurality of data objects written to a storage device, the method comprising:

maintaining respective temperature values for one or more of the plurality of data objects;

maintaining temporal data representing the order in which data objects have been retrieved from the storage device;

identifying the data objects in the data cache having an associated temperature value lower than a threshold value; and

deleting, from the data cache, the one or more data objects from the identified data objects that have been least recently retrieved from the storage device.

25. The method of claim 24 further including the step of increasing the threshold value if no data objects in the data cache have an associated temperature value lower than the threshold value.

26. The method of claim 24 wherein the temperature value has been specified by a user.

27. The method of claim 24 wherein the temperature value has been calculated by an automated process.

28. The method of claim 24 wherein the temperature value has been selected from an ordered set of temperature values.

29. The method of claim 28 wherein the threshold value has been selected from the ordered set of temperature values.

30. The method of claim 24 wherein the temperature value is a numerical value.

31. The method of claim 30 wherein the threshold value is a numerical value.