Flat dimensions are suitable when no parent-child relationships would normally exist between the dimension values. For example, dimension values named "Blue" and "Green" cannot logically be in a parent-child relationship; colors are not parents of each other in any ordinary sense. Thus, dimension values such as "Red", "Green", and "Blue" could be added to a flat dimension named "Color", as shown in the following diagram:
As this diagram shows, all dimension values in a flat dimension except for the root are leaf values, and navigation is possible only from the root to a leaf.
The leaf dimension values of flat dimensions can have records of product data tagged to them. In this case, the product data is accessed by navigation to the dimension values.
However, dimension values that do not have records tagged to them can also be useful in searches. Such dimension values can be selected to refine existing navigation states. For example, suppose that the dimension value "blue" has no records tagged to it. If the navigation state contains "blue" alone, no products will appear in the results list. If the current navigation state is "women's winter jackets", however, selecting the dimension value "blue" in the flat dimension shown above refines the navigation state to "women's blue winter jackets".
Flat dimensions and their dimension values are generated automatically when you load source data records into CAS. For information about how to configure the automatic generation of flat dimensions, see Creating dimensions, Endeca record properties, and Endeca records.
