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What is the difference between a star schema and a snowflake schema? Do you use them?

🟡 Medium Conceptual Mid level
1Times asked
Jul 2026Last seen
Jul 2026First seen

💡 Model Answer

A star schema is a dimensional model where a central fact table is connected directly to denormalized dimension tables. Each dimension contains all attributes, making queries fast because they involve simple joins. A snowflake schema normalizes dimensions into multiple related tables, reducing redundancy and storage space but adding more joins. Use a star schema when query performance and simplicity are paramount, such as in OLAP reporting. Use a snowflake schema when storage efficiency and data integrity are critical, or when dimensions have many optional attributes. In my experience, I design a star schema for the main reporting layer and occasionally denormalize parts of a snowflake to balance performance and storage.

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