Star schema is relational schema which is follow the concept of facts and dimensions. Fact table is used to store the event like login and dimension tables are used to store the reference data of the partitural event. In star schema , tables are completely denormalized because of this query performance time is very fast.
Snowflaking is a method of normalizing the dimension tables in a STAR schema. When we normalize all the dimension tables entirely, the resultant structure resembles a snowflake with the fact table in the middle. In the snowflake schema , one fact table is linked to multiple dimension table and each dimension table is linked to another dimension table. In snowflake schema , table are in normalized form.
|Sr. No.||Key||Star Schema||Snowflake Schema|
Star schema is relational schema which is follow the concept of facts and dimensions
A snowflake schema is an extension of the star schema
Work best in any data warehouse/ data mart
Better for small data warehouse/data mart.
High Data redundancy
Low data redundancy
It is very fast
It is slower than star schema
Tables in database are not normalized.
Tables in database are normalized.