Once the architects have defined their source systems, they are ready to design their target warehouses. Typically the schema of a data warehouse is in the shape of a star. The nucleus, or center of the star, contains a fact table . The facts within this table are measures of interest to business strategists, such as sales units and revenues. The fact table is surrounded by dimensions tables , which are objects within a business strategist's environment that relate to these measures.
Dimensions can include such items as products and fiscal periods.
Once both the source and the target system have been defined, the next step is to map the two together. Mapping within OWB occurs at two levels. The first, high-level mapping, indicates the source and target modules. OWB features a built-in transformation library from which users can pick prefabricated transformations. Prior to moving the data from the source to the target database, a data-warehouse architect has to deploy the warehouse.