Fact Constellation or Galaxy Schema
Fact Constellation:
- Multiple fact tables share dimension tables.
- This schema is viewed as collection of stars hence called galaxy schema or fact constellation.
- Sophisticated application requires such schema.
Case Study:
- Afco Foods & Beverages is a new company which produces dairy, bread and meat products with production unit located at Baroda.
- There products are sold in North, North West and Western region of India.
- They have sales units at Mumbai, Pune , Ahmadabad ,Delhi and Baroda.
- The President of the company wants sales information.
Sales Information
- Report: The Number of units sold.
- 113
- Report : The Number of units sold over Time.
Building Data Warehouse
Data Selection
- Data Preprocessing
- Fill missing values
- Remove inconsistency
- Data Transformation & Integration
- Data Loading
Data in warehouse is stored in form of fact tables and dimension tables.
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