Guide to Data Warehousing and Business Intelligence
A Fact Table in a dimensional model consists of one or more numeric facts of importance to a business. Examples of facts are as follows:
Businesses have a need to monitor these "facts" closely and to sum them using different "dimensions". For example, a business might find the following information useful:
Businesses will often need to sum facts by multiple dimensions:
In addition to numeric facts, fact table contain the "keys" of each of the dimensions that related to that fact (e.g Customer Nbr, Product ID, Store Nbr). Details about the dimensions (e.g customer name, customer address) are stored in the dimension table (i.e. customer).