4 Key Differences Between Data Warehouse Fact and Dimension Tables

Fact and dimension tables are the two foundational structures in data warehouse design. Fact tables store quantitative, measurable metrics (sales totals, transaction counts) and come in several types: transactional, periodic snapshot, accumulating snapshot, and factless. Dimension tables provide descriptive context for those metrics and include types such as slowly changing dimensions (SCD Types 1–3), conformed/aligned dimensions, junk dimensions, and role-playing dimensions. Together they form star and snowflake schemas. The post outlines how each table type functions, their use cases, and how they interrelate to enable effective business intelligence and analytical reporting.