STAR schema and Snowflake Schema

Item	SNOWFLAKE SCHEMA	STAR SCHEMA
Ease of use	More complex queries and hence less easy to understand	Less complex queries and easy to understand
Query performance	More foreign keys-and hence more query execution time	Less no. of foreign keys and hence lesser query execution time
Normalization	Has normalized tables	Has De-normalized tables
Type of datawarehouse	Good to use for small datawarehouses/datamarts	Good for large datawarehouses
Joins	Higher number of Joins	Fewer Joins
Dimension table	It may have more than one dimension table for each dimension	Contains only single dimension table for each dimension
When to use	When dimension table is relatively big in size, snow-flaking is better as it reduces space.	When dimension table contains less number of rows, we can go for Star schema.
Ease of maintenance/change	No redundancy and hence more easy to maintain and change	Has redundant data and hence less easy to maintain/change