US 6,636,870 B2 · Storing multidimensional data in a relational database management system

Abstract

Techniques are provided which address the problems associated with the conventional approaches for storing multidimensional data in a relational database system. According to technique, the many foreign key values of each row in the fact table are mapped to and replaced by a “replacement” value. A mapping function is provided that derives a replacement value from any given combination of foreign key values, and an inverse mapping function is provided to reproduce the combination of foreign key values given the replacement value. A mapping function is selected such that the foreign key value combinations of multidimensional values that are conceptually related to each other map to values that are close to each other. The rows in the fact table are then stored within the fact table in the sorted order, thus causing values that are conceptually related to each other to be stored physically near each other within the fact table. Various techniques are provided for generating the replacement value from the foreign key values by subdividing the multidimensional cube that contains all of the multidimensional values into smaller sub-cubes that are referred to as tiles. Variations on the tiling mechanism are provided. According to one approach, the cube is sub-divided into tiles based on the members of a particular level of a hierarchical dimension. According to another tiling approach, the tiles themselves may be subdivided into smaller tiles to create a hierarchy of tiles.

Claims26

Dependent claims

A method for generating a replacement value associated with a data cell of a multidimensional cube representing multidimensional data stored in relational tables, the method comprising the steps of:

generating a tile position value that represents a position of a tile in which the cell resides relative to other tiles within the multidimensional cube;
generating a local position value that represents a position of the cell relative to other cells within the tile in which the cell resides;
and
generating a replacement value based on the tile position value and the local position value.

1 more element

A method for manipulating multidimensional data in relational tables, the method comprising the steps of:

maintaining a fact table for storing cell values that are associated with a plurality of dimensions;
receiving a request to store a particular cell value that is associated with a particular set of dimension key values, the particular set of dimension key values including one dimension key value for each of the plurality of dimensions;
generating a tile position that represents a position of a tile in which the particular cell value resides relative to other tiles within a multidimensional cube representing the multidimensional data;
generating a local position that represents a position of the particular cell value relative to other cells within the tile in which the cell resides;
generating a replacement value based on the tile position value and the local position value;
and
storing within the fact table the particular cell value, and the replacement value in association with the particular cell value.

4 more elements

A computer-readable medium carrying one or more sequences of instructions for manipulating multidimensional data in relational tables, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

maintaining a fact table for storing cell values that are associated with a plurality of dimensions;
receiving a request to store a particular cell value that is associated with a particular set of dimension key values, the particular set of dimension key values including one dimension key value for each of the plurality of dimensions;
generating a tile position that represents a position of a tile in which the particular cell value resides relative to other tiles within a multidimensional cube representing the multidimensional data;
generating a local position that represents a position of the particular cell value relative to other cells within the tile in which the cell resides;
generating a replacement value based on the tile position value and the local position value;
and
storing within the fact table the particular cell value, and the replacement value in association with the particular cell value.

4 more elements

Dependencies are inferred from the claim text.

Storing multidimensional data in a relational database management system

Life of this patent

Storing multidimensional data in a relational database management system

Life of this patent

Abstract

Claims26