Star Schema: A Star schema is a schema in which a fact is connected to multiple dimensions and dimension table doesn't have any parent table.
Snowflake Schema: A SnowFlake schema is a schema in which a fact is connected to multiple dimensions and dimension table have one or more parent table. In other words, snowflake schema is "a star schema with dimensions connected to some more dimensions"
| Star Schema | Snowflake Schema |
|---|---|
Has data redundancy(duplicate data) and difficult
to maintain
|
No data redundancy and easy to maintain
|
Has De-normalized tables
|
Has Normalized tables
|
Suitable for large datawarehouse
|
Suitable for small datawarehouse
|
Dimension table is not connected to other dimension table
|
Dimension table is connected to another dimension table
|
Queries are less complex and easy to understand
|
Queries are more complex and difficult to understand
|
Has less number of joins
|
Has more number of joins
|
Less query execution time
|
More execution time because of complex queries
|
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