Thursday, November 14, 2013

Difference between Star schema and Snowflake schema

    Star Schema

Snowflake Schema

1.  In the Star schema the    fact table was surrounded by multiple dimension tables which are directly connected to the fact through Foreign key

1.  One or more dimension    tables are indirectly connected to the Fact table through the intermediate Dimension tables
2. Both Fact and Dimension tables are in de-normalized form 2. Dimension Tables are in Normalized form but Fact Table is still in de-Normalized form
3. Less number of Joins 3. Large number of Joins
4. Has Redundant data 4. No redundancy
5. Not easy to maintain and change 5. Easy to maintain and change