Data Mining And Data Warehousing
Star Schema
Star Schema
A Star Schema is a type of database schema used in data warehousing that organizes data into fact and dimension tables to optimize query performance and ease of use.
Components:
Fact Table:
Central table.
- Contains measurable, quantitative data (e.g., sales, revenue).
- Has foreign keys referencing dimension tables.
Dimension Tables:
- Surround the fact table (hence "star").
- Contain descriptive attributes (e.g., date, product, customer, location).
- Used for filtering, grouping, and labeling.
Example:
Imagine a retail sales database:
- Fact Table: Sales (sales_id, product_id, customer_id, date_id, store_id, sales_amount)
Dimension Tables:
- Product (product_id, product_name, category)
- Customer (customer_id, name, region)
- Date (date_id, day, month, year)
- Store (store_id, store_name, location)