TYPES OF FACTS IN DATA WAREHOUSE Types of Facts in Data Warehouse A fact table is the one which consists of the measurements, metrics or facts of business process. These measurable facts are used to know the business value and to forecast the future business. The different types of facts are explained in detail below.
Additive facts are facts that can be summed up through all of the dimensions in the fact table. A sales fact is a good example for additive fact.
Semi-additive facts are facts that can be summed up for some of the dimensions in the fact table, but not the others. Eg: Daily balances fact can be summed up through the customers dimension but not through the time dimension.
Non-additive facts are facts that cannot be summed up for any of the dimensions present in the fact table. Eg: Facts which have percentages, ratios calculated.
Factless Fact Table:
In the real world, it is possible to have a fact table that contains no measures or facts. These tables are called "Factless Fact tables".
Eg: A fact table which has only product key and date key is a factless fact. There are no measures in this table. But still you can get the number products sold over a period of time.
A fact tables that contain aggregated facts are often called summary tables.