Star Schema and Snowflake Schema are two common data modeling techniques used in a Data Warehouse to organize data for analytical queries (OLAP systems).<\/p>\n\n\n\n
They are mainly used in dimensional modeling for reporting and business intelligence.<\/p>\n\n\n\n
A Star Schema is a simple database structure where:<\/p>\n\n\n\n
Fact Table (center)
Sales_Fact<\/p>\n\n\n\n
Connected Dimension Tables:
Customer_Dim
Product_Dim
Date_Dim
Region_Dim<\/p>\n\n\n\n
The fact table contains:<\/p>\n\n\n\n
Sales_Fact:<\/p>\n\n\n\n Customer_Dim:<\/p>\n\n\n\n | customer_id | name | city | segment |<\/p>\n\n\n\n A Snowflake Schema is an extension of the Star Schema where:<\/p>\n\n\n\n Sales_Fact \u2192 Product_Dim \u2192 Category_Dim Instead of storing all product information in one table, it is broken into multiple related tables.<\/p>\n\n\n\n Most modern cloud data warehouses like:<\/p>\n\n\n\n Support both Star and Snowflake schema designs.<\/p>\n\n\n\n Star Schema is a simple dimensional model with one fact table connected to denormalized dimension tables, while Snowflake Schema is a normalized version where dimension tables are split into multiple related tables to reduce redundancy.<\/p>\n\n\n\n Star Schema = Simple, Fast, Easy Both are important data modeling techniques in Data Warehousing and Data Engineering.<\/p>\n\n\nsale_id<\/th> customer_id<\/th> product_id<\/th> date_id<\/th> region_id<\/th> amount<\/th><\/tr><\/thead><\/table><\/figure>\n\n\n\n Advantages of Star Schema<\/h2>\n\n\n\n
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Disadvantages<\/h2>\n\n\n\n
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Snowflake Schema<\/h1>\n\n\n\n
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Structure Example<\/h2>\n\n\n\n
Sales_Fact \u2192 Customer_Dim \u2192 City_Dim \u2192 Country_Dim<\/p>\n\n\n\nAdvantages of Snowflake Schema<\/h2>\n\n\n\n
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Disadvantages<\/h2>\n\n\n\n
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Star Schema vs Snowflake Schema<\/h1>\n\n\n\n
Feature<\/th> Star Schema<\/th> Snowflake Schema<\/th><\/tr><\/thead> Structure<\/td> Simple<\/td> Complex<\/td><\/tr> Normalization<\/td> Low<\/td> High<\/td><\/tr> Query Speed<\/td> Faster<\/td> Slightly slower<\/td><\/tr> Storage<\/td> More space<\/td> Less space<\/td><\/tr> Joins<\/td> Fewer<\/td> More<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n When to Use Star Schema?<\/h1>\n\n\n\n
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When to Use Snowflake Schema?<\/h1>\n\n\n\n
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Real-World Usage<\/h1>\n\n\n\n
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Interview Answer (Short Version)<\/h1>\n\n\n\n
Final Summary<\/h1>\n\n\n\n
Snowflake Schema = Structured, Efficient, Complex<\/p>\n\n\n\n