Record for a multidimensional database with flexible paths

• US 6,446,059 B1
• Filed: 06/22/1999
• Issued: 09/03/2002
• Est. Priority Date: 06/22/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Pasumansky, Mosha, Berger, Alexander, Netz, Amir
• Primary Examiner(s): Mizrahi, Diane D.
• Application Number:
  US09/338,207
• Time in Patent Office: 1,169 Days
• Field of Search: 707/1, 707/2, 707/3, 707/4, 707/5, 707/6, 707/100, 707/102, 707/103, 707/200
• US Class Current: 1/1
• CPC Class Codes: G06F 16/283 Multi-dimensional databases or data warehouses, e.g. MOLAP or ROLAP
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

Creating and maintaining cell data records in a multidimensional database is disclosed using flexible dimension paths is disclosed. The systems and methods of the invention define an efficient mechanism to specify a cell'"'"'s location within the multidimensional database where there are hierarchies of levels within a dimension. The flexible dimension path does not change when a member is moved from a first point to a second point on a dimension thereby avoiding the need to rebuild the OLAP database. The format used lends itself well to indexing, and also to creating aggregations of the cell data.

Claims

1. A computerized method for creating a cell record for a multidimensional database, the method comprising:

maintaining a set of mappings from a rigid dimension path to a unique memberid;

receiving a measurement data item for a cell, said cell identified by a first member, said first member having a first dimension and a first level;

determining a first rigid dimension path for the first member;

if the first rigid path is in the set of mappings, inserting a first flexible dimension path corresponding to the unique memberid mapped to the first rigid dimension path into a system path field of the cell record, otherwise inserting the first rigid dimension path into a system path field of the cell record; and

inserting the measurement data item into a measurement field of the cell record.

2. The computerized method of claim 1, wherein determining the first rigid dimension path comprises:

determining a set of dimension members on a path between the first dimension member and a top-level member, said path including the top-level member and the first dimension member; and

for each dimension member in the set of dimension members, performing the tasks of;

determining a member number, and

concatenating the member number into the first rigid dimension path.

3. The computerized method of claim 2, wherein the member number is determined by the dimension member'"'"'s order among a set of siblings for the member.

4. The computerized method of claim 1, wherein the cell is further identified by a second member, said second member having a second dimension and a second level, and further comprising:

determining a second rigid dimension path for the second member; and

concatenating a second flexible dimension path corresponding to the unique memberid mapped to the second rigid path into the system path field if the second rigid path is in the set of mappings, otherwise concatenating the second rigid path into the system path.

5. The computerized method of claim 4, wherein determining the second rigid dimension path comprises:

determining a set of dimension members on a path between the second dimension member and a top-level member, said path including the top-level member and the second dimension member; and

for each dimension member in the set of dimension members, performing the tasks of;

determining a member number, and

concatenating the member number into the second rigid dimension path.

6. The computerized method of claim 4, wherein the member number is determined by the dimension member'"'"'s order among a set of siblings for the member.

7. A computerized method for determining an aggregation measure, the method comprising:

identifying an aggregation measure and an aggregation system path, said aggregation system path specifying an aggregation dimension and an aggregation level;

if a flexible dimension path exists in the aggregation dimension then converting the flexible dimension path to a rigid dimension path;

for each record of a plurality of records, each record having a system path, said system path having a rigid dimension path, said rigid dimension path having a plurality of level components, performing the following tasks;

setting a level component corresponding to the aggregation level to a null value, and

setting each level component corresponding to a level below the aggregation level to the null value;

selecting a subset of the plurality of records where the system path equals the aggregation system path; and

summing a measure corresponding to the aggregation measure in each record of the subset to create an aggregated measure.

8. The method of claim 7, further comprising restoring to a previous value each of the level components set to a null value.

9. The method of claim 8, wherein restoring to a previous value comprises rolling back a database transaction.

10. The method of claim 8, wherein an aggregation record having the aggregation system path and a measure corresponding to the aggregated measure is stored in a cache.

11. A computer-readable medium having computer-executable instructions for performing a method comprising:

maintaining a set of mappings from a rigid dimension path to a unique memberid;

receiving a measurement data item for a cell, said cell identified by a first member, said first member having a first dimension and a first level;

determining a first rigid dimension path for the first member;

if the first rigid path is in the set of mappings, inserting a first flexible dimension path corresponding to the unique memberid mapped to the first rigid dimension path into a system path field of the cell record, otherwise inserting the first rigid dimension path into a system path field of the cell record; and

inserting the measurement data item into a measurement field of the cell record.

12. The computer-readable medium of claim 11, wherein determining the first rigid dimension path comprises:

determining a set of dimension members on a path between the first dimension member and a top-level member, said path including the top-level member and the first dimension member; and

for each dimension member in the set of dimension members, performing the tasks of;

determining a member number, and

concatenating the member number into the first rigid dimension path.

13. The computer-readable medium of claim 12, wherein the member number is determined by the dimension member'"'"'s order among a set of siblings for the member.

14. The computer-readable medium of claim 11, wherein the cell is further identified by a second member, said second member having a second dimension and a second level, and further comprising:

determining a second rigid dimension path for the second member; and

concatenating a second flexible dimension path corresponding to the unique memberid mapped to the second rigid path into the system path field if the second rigid path is in the set of mappings, otherwise concatenating the second rigid path into the system path.

15. The computer-readable medium of claim 14, wherein determining the second rigid dimension path comprises:

determining a set of dimension members on a path between the second dimension member and a top-level member, said path including the top-level member and the second dimension member; and

for each dimension member in the set of dimension members, performing the tasks of;

determining a member number, and

concatenating the member number into the second rigid dimension path.

16. The computer-readable medium of claim 14, wherein the member number is determined by the dimension member'"'"'s order among a set of siblings for the member.

17. A computer-readable medium having computer-executable instructions for performing a method comprising:

identifying an aggregation measure and an aggregation system path, said aggregation system path specifying an aggregation dimension and an aggregation level;

if a flexible dimension path exists in the aggregation dimension then converting the flexible dimension path to a rigid dimension path;

for each record of a plurality of records, each record having a system path, said system path having a rigid dimension path, said rigid dimension path having a plurality of level components, performing the following tasks;

setting a level component corresponding to the aggregation level to a null value, and

setting each level component corresponding to a level below the aggregation level to the null value;

selecting a subset of the plurality of records where the system path equals the aggregation system path; and

summing a measure corresponding to the aggregation measure in each record of the subset to create an aggregated measure.

18. The computer-readable medium of claim 17, further comprising restoring to a previous value each of the level components set to a null value.

19. The computer-readable medium of claim 18, wherein restoring to a previous value comprises rolling back a database transaction.

20. The computer-readable medium of claim 18, wherein an aggregation record having the aggregation system path and a measure corresponding to the aggregated measure is stored in a cache.

21. A computerized system comprising:

a processor and a computer-readable medium;

an operating environment executing on the processor from the computer-readable medium;

a map table;

a fact data store;

a local data store; and

an OLAP server executing under the control of the operating environment and operative to perform the tasks of;

reading a plurality of detail records from the fact data store,

for each of the plurality of detail records performing the tasks of;

determining a system path to the cell record, said system path including a flexible dimension record if a rigid dimension path associated with the cell record appears in the map table,

creating a cell record having a system path and at least one measure corresponding to a value from the detail record, and

storing the cell record in the local data store.

22. The computerized system of claim 21, wherein the fact data store is a relational database.

23. The computerized system of claim 21, wherein the local data store is a relational database system.