Types of Facts in Data Warehousing

A fact table is the central table in a star schema of a data warehouse. A fact table stores quantitative information for analysis and is often denormalized form.

A fact table works with dimension tables. A fact table holds the data to be analyzed, and a dimension table stores data about the ways in which the data in the fact table can be analyzed.
Thus, fact tables typically has two types of columns, foreign keys to dimension tables and measures those that contain numeric facts. A fact table can contain fact’s data on detail or aggregated level.
Eg: Sales, Cost, Profit, and many more.

Types of Facts

• Non-Additive
• Semi-Additive
• Additive

Additive

Additive facts are facts that can be summed up through all of the dimensions in the fact table.

Eg: Sales fact.

Semi-Additive

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

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.