Systems and methods for proactive caching utilizing OLAP variants

• US 7,269,581 B2
• Filed: 03/28/2003
• Issued: 09/11/2007
• Est. Priority Date: 03/28/2003
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Petculescu, Cristian, Conlon, Thomas P., Netz, Amir
• Primary Examiner(s): Rimell; Sam
• Assistant Examiner(s): BELL, CORY C
• Application Number:
  US10/402,000
• Publication Number:
  US 20040193576A1
• Time in Patent Office: 1,628 Days
• Field of Search: 707/1, 707/3
• US Class Current: 707/600
• CPC Class Codes: G06F 16/283 Multi-dimensional databases or data warehouses, e.g. MOLAP or ROLAP
• CPC Class Codes: Y10S 707/954 Relational
• CPC Class Codes: Y10S 707/957 Multidimensional
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching

Abstract

The present invention leverages MOLAP performance for ROLAP objects (dimensions, partitions and aggregations) by building, in a background process, a MOLAP equivalent of that object. When the background processing completes, queries are switched from ROLAP queries to MOLAP queries. When changes occur to relevant relational objects (such as tables that define content of OLAP objects), an OLAP object is switched back to a ROLAP mode, and all relevant caches are dropped while, as a background process, a new MOLAP equivalent is created.

Claims

1. A system for caching information, comprising:

a multidimensional objects interface that allows for accessing at least one multidimensional ROLAP object providing dynamic multidimensional analysis data derived from a database;

a cache interface that allows for accessing and controlling at least one MOLAP cache providing dynamic multidimensional analysis data derived from the multidimensional ROLAP object, the cache interface redirects any access to the Multidimensional On-line Analytical Processing MOLAP cache to the multidimensional ROLAP object when the MOLAP cache is being built or rebuilt and until the cache completes building or rebuilding; and

at least one analysis component coupled to the multidimensional Relational On-line Analytical Processing ROLAP object and the MOLAP cache for proactively controlling access to the multidimensional ROLAP object and the MOLAP cache, the at least one analysis component process queries utilizing the multidimensional ROLAP object and the MOLAP cache based upon at least a determination by the cache interface.

2. The system of claim 1, the database comprising a relational database.

3. The system of claim 1, the multidimensional ROLAP object comprising real-time access analysis data and the MOLAP cache comprising low latency access analysis data.

4. The system of claim 1, the analysis component comprises a Unified Dimensional Model (UDM) component that provides access to disparate data sources.

5. The system of claim 1, the analysis component, comprising:

at least one input for determining when to proactively control the MOLAP cache; and

a query interpreter for receiving and qualifying queries based upon the input.

6. The system of claim 5, the input comprising at least one of a user input and a system input for proactively controlling the MOLAP cache.

7. The system of claim 6, the system input comprising a database update notification.

8. The system of claim 6, the user input comprising at least one of a quiet time delay, a quiet time delay override, a forced refresh time, and a user initiated partial MOLAP cache rebuild.

9. The system of claim 6, the system input comprising at least one of a last database update tracker, tables affecting On-line Analytical Processing (OLAP) objects, and a dependent OLAP objects data source tracker.

10. The system of claim 1, the analysis component having proactive caching operational modes comprising at least one of a ROLAP mode, a MOLAP mode, and a MOLAP and ROLAP hybrid (MOLAP/ROLAP) mode.

11. The system of claim 10, the ROLAP mode operatively triggered by at least one of quiet time delay met, quiet time delay override met, forced refresh time met, and database updated.

12. The system of claim 10, the MOLAP mode operatively triggered by at least one of:

equivalent query data available from both a MOLAP cache and a ROLAP object; and

a user demand.

13. The system of claim 10, the MOLAP/ROLAP mode operatively triggered by at least one of both real-time and low latency queries required and partial rebuilding of a MOLAP cache required.

14. The system of claim 1, the analysis component having capabilities to process multiple queries each requiring different proactive cache handling.

15. The system of claim 1, the analysis component having capabilities to process a parsed query, each part requiring different proactive cache handling.

16. The system of claim 1, the analysis component comprising an adaptive tuning component for optimizing the analysis component.

17. The system of claim 16, the adaptive tuning component, comprising:

a query interpreter for handling queries and instigating query sessions with the multidimensional ROLAP object and the MOLAP cache;

a result comparator operatively connected to the query interpreter for determining differences between the query sessions of the multidimensional ROLAP object and the MOLAP cache; and

a performance optimizer operatively connected to the result comparator for optimizing the query interpreter based on the differences determined by the result comparator.

18. A device employing the system of claim 1 comprising at least one from a group consisting of a computer, a server, and a handheld electronic device.

19. A method of caching data, comprising:

providing at least one multidimensional ROLAP object providing dynamic multidimensional analysis data derived from a database;

constructing at least one MOLAP cache providing dynamic multidimensional analysis data derived from the at least one multidimensional ROLAP object;

switching an operational mode of an analysis component to access the MOLAP cache only for query analysis;

switching the analysis component operational mode to access the multidimensional ROLAP object from which a MOLAP cache is derived during a building or rebuilding of the MOLAP cache and back to the MOLAP cache after building or rebuilding completes; and

analyzing and processing queries via the analysis component.

20. The method of claim 19, further comprising:

determining if any changes to relevant multidimensional ROLAP objects have occurred; and

switching the analysis component operational mode to access the multidimensional ROLAP objects when relevant changes have occurred.

21. The method of claim 20, further comprising:

removing all MOLAP cache related to the relevant changes; and

rebuilding the MOLAP cache based on changed multidimensional ROLAP objects.

22. The method of claim 19, further comprising:

determining if a query requires at least one selected from the group of low latency data and real-time data.

23. The method of claim 22, further comprising:

switching the analysis component to a MOLAP/ROLAP operational mode when both low latency and real-time data are required.

24. The method of claim 19, the database comprising a relational database.

25. The method of claim 19, the analysis component comprises a UDM component that facilitates access to a plurality of data sources.

26. The method of claim 19, the analysis component having operational modes comprising at least one selected from the group consisting of a MOLAP mode, a ROLAP mode, and a MOLAP/ROLAP mode.

27. A method of proactive caching, comprising:

providing an input related to determining an operational mode;

determining the operational mode based, at least in part, upon the input;

providing at least one multidimensional ROLAP object providing dynamic multidimensional analysis data derived from a database;

building at least one MOLAP cache providing dynamic multidimensional analysis data derived from at least one multidimensional ROLAP object;

switching an analysis component having a plurality of operational modes to the determined operational mode;

switching the analysis component operational mode to access the multidimensional ROLAP object from which a MOLAP cache is derived during a building or rebuilding of the MOLAP cache and back to the determined operational mode after building or rebuilding completes; and

processing queries via the analysis component utilizing the determined operational mode.

28. The method of claim 27, further comprising:

determining if any changes to relevant multidimensional ROLAP objects have occurred; and

switching the analysis component operational mode to access the multidimensional ROLAP objects when relevant changes have occurred.

29. The method of claim 28, further comprising:

removing all MOLAP cache related to the relevant changes; and

rebuilding the MOLAP cache based on the changed multidimensional ROLAP objects.

30. The method of claim 27, further comprising:

determining relevant changes during the building of the MOLAP cache; and

cancelling the building of the MOLAP cache when relevant changes occur if the building of the MOLAP cache has not yet completed and restarting building of the MOLAP cache.

31. The method of claim 27, the input comprising at least one selected from the group consisting of at least one user input and at least one system input.

32. The method of claim 31, the user input comprising at least one selected from the group consisting of a low latency query request and a real-time query request.

33. A method of proactive caching, comprising:

providing at least one multidimensional ROLAP object providing dynamic multidimensional analysis data derived from a database;

switching an analysis component operational mode to access the at least one multidimensional ROLAP object;

building at least one MOLAP cache providing dynamic multidimensional analysis data derived from at least one multidimensional object;

switching an analysis component operational mode to access the at least one MOLAP cache;

providing an input for designating data;

determining if any changes to relevant multidimensional ROLAP objects have occurred;

rebuilding the MOLAP cache based on the changed relevant multidimensional ROLAP objects,

switching the analysis component operational mode to access the multidimensional ROLAP objects when relevant changes have occurred;

switching the analysis component operational mode to access the MOLAP cache only after rebuilding the MOLAP cache; and

processing queries via the analysis component.

34. The method of claim 33, the input comprising data desired to be updated.

35. The method of claim 34, changes to relevant multidimensional ROLAP objects comprising changes to the data being updated.

36. The method of claim 33, the input comprising information for linking data to relevant multidimensional ROLAP objects.

37. A method of proactive caching, comprising:

providing at least one multidimensional ROLAP object providing dynamic multidimensional analysis data derived from a database;

switching an analysis component operational mode to access the at least one multidimensional ROLAP object;

building at least one MOLAP cache providing dynamic multidimensional analysis data derived from at least one multidimensional object;

switching an analysis component operational mode to access the MOLAP cache;

providing an input for determining a cache rebuild parameter;

determining if the cache rebuild parameter has been satisfied;

rebuilding the MOLAP cache based on relevant multidimensional ROLAP objects;

switching an operational mode of an analysis component to access the multidimensional ROLAP objects; and

switching the analysis component operational mode to access the MOLAP cache only after rebuilding the MOLAP cache; and

processing queries via the analysis component.

38. A method of claim 37, the cache rebuild parameter comprising at least one selected from the group consisting of a forced refresh rate, a quiet time delay, and a quiet time delay override.