What is the purpose of a fact table in a data warehouse?

• A. To store the results of calculations.
• B. To store raw data.
• C. It stores metadata about the data warehouse.
• D. It tracks user access permissions.

Answer: (A)

In a data warehouse, the fact table is where the numeric measurements that you analyze reside. It captures the outcomes of business processes as quantitative values—such as sales amount, quantity sold, or total cost—that you want to aggregate and compare across different perspectives. Each row represents a transaction or event and includes foreign keys to related dimension tables (like time, product, customer, or store) to give those measures context for slicing and dicing in reports and analyses. Because its main purpose is to hold these actionable metrics and their calculations for analysis, it’s the right place for the results of calculations.

The other options describe things that aren’t the primary role of a fact table: raw data is typically stored in staging or raw data stores; metadata about the data warehouse is kept in a separate metadata catalog; and user access permissions are part of security controls, not the fact table itself.