Snowflake schema
A variant of the star schema where dimension tables are normalized into several levels — e.g. product → category → department in separate tables. The diagram branches like a snowflake. Less redundancy, more joins.
Trade-off versus the star schema: saves storage and avoids update anomalies (a category name lives in one place), but requires more joins → slower queries and harder for BI users to navigate. In practice: with today's cheap storage the star schema is often preferred for performance. The snowflake schema is justified when dimensions are large and partly shared, or when data integrity weighs heaviest. The name is unrelated to the company Snowflake (the cloud data warehouse) — a common confusion. A hybrid form, "starflake", exists.