The star schema is created when all the dimension tables directly link to the fact
table. Since the graphical representation resembles a star it is called a star schema. It must be noted that the foreign keys in the fact table link to the primary key of the
dimension table. This sample provides the star schema for a sales_ fact for the year
1998. The dimensions created are Store, Customer, Product_class and time_by_day.
The Product table links to the product_class table through the primary key and
indirectly to the fact table. The fact table contains foreign keys that link to the
dimension tables.