Relational to multidimensional mapping

Chapter 12 Creating Mappings

Relational to multidimensional mapping

OLAP cubes are usually filled with data from a data warehouse database.

You can link PDM objects to create a relational to multidimensional mapping between physical objects and OLAP objects. With this link, it will be possible to generate text files containing data warehouse data. These text files can be used to populate OLAP cubes.

Automatic mapping
When you use the Rebuild Cubes feature to create cubes and dimensions from fact and dimension tables, the mapping between source tables and OLAP objects is automatically performed. For more information about the Rebuild Cubes feature, see section Rebuilding Cubes in chapter Building Multidimensional Diagrams in the Data Modeling guide.

The relational to multidimensional mapping is used to generate cube data in text files to be loaded by OLAP engines.

Mapping a physical object to multidimensional objects

The mapping for a physical object (dimension or fact) is used to supply data for the cube dimensions or cube measures in OLAP databases. You can identify the tables or views used to populate OLAP cubes. The tables in the data source need not be of dimension or fact type. Once the source tables or views are identified, you can define mappings between attributes or measures and table columns.

Select sub-tab

The Select sub-tab displays the entire SQL statement used to select data in the data source. This statement is automatically generated.

The Generate Cube Data feature uses this SQL statement to fill the text files used to populate cubes in an OLAP database.

For more information on the generation of cube data, see the "Generating cube data" section in the "Working with PDMs" chapter in the Data Modeling guide.