What are the key differences between a star schema and a snowflake schema in data modeling
| Aspect | Star Schema | Snowflake Schema |
|---|---|---|
| Structure | Central fact table surrounded by dimension tables. | Dimension tables are further normalized into sub-dimensions or sub-levels. |
| Data Redundancy | Dimension tables often contain some data redundancy (denormalized). | Dimension tables are more normalized, resulting in less data redundancy. |
| Complexity | Generally simpler and easier to understand due to fewer tables and relationships. | More complex due to additional sub-dimensions and relationships, potentially more tables. |
| Storage Space | May require more storage space due to data redundancy. | Requires less storage space compared to star schema due to normalization. |
| Query Performance | Often offers better query performance, as denormalized tables reduce the need for joins. | Query performance may be slightly impacted due to the need for more joins. |