The snowflake schema is an extension of the star schema, where each point of the star explodes into more points. In a star schema, each dimension is represented by a single dimensional table, whereas in a snowflake schema, that dimensional table is normalized into multiple lookup tables, each representing a level in the dimensional hierarchy.
- The biggest advantage of snowflake schema is improved query performance.
- Reduces dimension table size.
- Additional maintenance efforts needed due to the increase number of lookup or detail tables