Cubes (PDM)

A cube is a collection of measures corresponding to values stored into each of its data cells.

The measures (see Measures (PDM)) are organized into dimensions (see Dimensions (PDM)) to provide for faster retrieval and drill-down.

Usually a cube is associated with a fact that allows to define and share measures among cubes.

In a multidimensional diagram, the cube represents an OLAP cube. Cubes need to be created and populated via a text file in the OLAP engine. This text file contains a query used to extract data from a data warehouse or operational database to fill the cubes in the OLAP engine, and is defined in the Query tab of the cube's property sheet.

• Creating a Cube
  You can create a cube using a Wizard or from the Toolbox, Browser, or Model menu.
• Cube Properties
  To view or edit a cube's properties, double-click its diagram symbol or Browser or list entry. The property sheet tabs and fields listed here are those available by default, before any customization of the interface by you or an administrator.
• Retrieving Multidimensional Objects
  During the design of a data warehouse, you will need to identify which of your tables and views will represent facts, and which dimensions. In this section, we will refer to both tables and views as being either:
• Generating Extraction Scripts
  You can model operational and data warehouse data structures in PDMs, and specify mappings between the operational data sources and the data warehouse to generate extraction scripts to populate the data warehouse with operational data.
• Generating Cube Data
  You can map physical tables (including those of type dimension or fact) to cube dimensions or cube measures in OLAP databases, and use these mappings to generate cube data in text files to be loaded by OLAP engines. When you use the Rebuild Cubes command to create cubes and dimensions from fact and dimension tables, mappings between source tables and OLAP objects are automatically created.