Q35: What is the difference between a Star Schema and a Snowflake Schema in Data Warehousing?
- Star Schema: A central Fact Table surrounded by denormalized Dimension Tables. It simplifies query design and speeds up read analytical performance by minimizing required JOIN operations.
- Snowflake Schema: A variant where dimension tables are normalized into sub-dimension entities. It reduces data redundancy, but requires more complex multi-table JOIN queries.
Key Takeaways
- Star Schemas denormalize dimension tables to simplify queries and maximize read performance.
- Snowflake Schemas normalize dimension tables to reduce storage redundancy.