Virtual dimensions in databases and method therefor

• US 6,473,764 B1
• Filed: 10/15/1999
• Issued: 10/29/2002
• Est. Priority Date: 10/15/1999
• Status: Active Grant

• Current Assignee: Zhigu Holdings Limited
• Original Assignee: Microsoft Corporation
• Inventors: Petculescu, Cristian, Netz, Amir
• Primary Examiner(s): Mizrahi, Diane D.
• Application Number:
  US09/418,807
• Time in Patent Office: 1,110 Days
• Field of Search: 707/102, 707/1, 707/2, 707/3, 707/4, 707/100, 707/200
• US Class Current: 707/603
• CPC Class Codes: G06F 16/283 Multi-dimensional databases or data warehouses, e.g. MOLAP or ROLAP
• CPC Class Codes: Y10S 707/956 Hierarchical
• CPC Class Codes: Y10S 707/957 Multidimensional
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

A method, apparatus, and software are disclosed for analyzing the data in an OLAP or other type of database. The data is analyzed as if it were indexed by desired dimensions without actually creating the dimensions. Relations known as virtual dimensions are defined in relation to existing base dimensions in the database rather than in relation to the underlying detailed data. Functions operating on these virtual dimensions are translated into functions that operate on the existing base dimensions. As a result, the need to perform certain precalculations is avoided, thereby promoting efficient use of computing resources.

Claims

1. A computer-implemented method for analyzing data in a database, the method comprising:

associating a selected property value of each one of a set of base dimension members with a corresponding one of the set of base dimension members;

determining a set of distinct property values for the set of base dimension members; and

for each distinct property value, computing an aggregate of the base dimension members that have that distinct property value.

2. The method, according to claim 1, wherein associating a selected property value of each one of the set of base dimension members with a corresponding one of the set of base dimension members is performed when a base dimension members hierarchy is created.

3. The method, according to claim 2, further comprising reading the base dimension members hierarchy before associating a selected property value of each one of the set of base dimension members with a corresponding one of the set of base dimension members.

4. The method, according to claim 2, further comprising reading the base dimension members hierarchy on a demand basis.

5. The method, according to claim 1, wherein determining the set of distinct property values for the set of base dimension members comprises scanning the property values of all of the base dimension members.

6. The method, according to claim 1, wherein determining the set of distinct property values for the set of base dimension members comprises querying the database for the set of distinct property values.

7. The method, according to claim 1, wherein determining the set of distinct property values for the set of base dimension members comprises maintaining a list of distinct property values in a memory.

8. The method, according to claim 1, wherein computing the aggregates is performed before a user request to analyze the data.

9. The method, according to claim 1, wherein computing the aggregates is performed on a demand basis.

10. The method, according to claim 1, wherein computing the aggregate of the base dimension members that have a distinct property value comprises creating a multidimensional expression language (MDX) expression as a function of that distinct property value.

11. The method, according to claim 1, wherein computing the aggregate of the base dimension members that have a distinct property value comprises referencing a predefined set of instructions for computing the aggregate.

12. The method, according to claim 1, wherein computing the aggregates comprises sorting the base dimension members into subsets according to their property values.

13. A computer-readable medium for analyzing data in a database, the computer-readable medium having computer-executable instructions for:

associating a selected property value of each one of a set of base dimension members with a corresponding one of the set of base dimension members;

determining a set of distinct property values for the set of base dimension members; and

for each distinct property value, computing an aggregate of the base dimension members that have that distinct property value.

14. The computer-readable medium, according to claim 13, having further computer-executable instructions for computing the aggregate of the base dimension members that have a distinct property value at least in part by creating a multidimensional expression language (MDX) expression as a function of that distinct property value.

15. The computer-readable medium, according to claim 13, having further computer-executable instructions for computing the aggregate of the base dimension members that have a distinct property value at least in part by referencing a predefined set of instructions for computing the aggregate.

16. The computer-readable medium, according to claim 13, having further computer-executable instructions for computing the aggregates at least in part by sorting the base dimension members into subsets according to their property values.

17. A computer arrangement for analyzing data in a database, the computer arrangement configured to:

associate a selected property value of each one of a set of base dimension members with a corresponding one of the set of base dimension members;

determine a set of distinct property values for the set of base dimension members; and

for each distinct property value, compute an aggregate of the base dimension members that have that distinct property value.

18. The computer arrangement, according to claim 17, further configured to compute the aggregate of the base dimension members that have a distinct property value at least in part by creating a multidimensional expression language (MDX) expression as a function of that distinct property value.

19. The computer arrangement, according to claim 17, further configured to compute the aggregate of the base dimension members that have a distinct property value at least in part by referencing a predefined set of instructions for computing the aggregate.

20. The computer arrangement, according to claim 17, further configured to compute the aggregates at least in part by sorting the base dimension members into subsets according to their property values.