Multidimensional Data Model
Main elements
- Measures (quantitive facts) - revenue, cost, profit
- Dimensions (qualitative attributes) - time, product, customer
- Hierarchies (levels of granularity) - year, quarter, month, day
Star Schema
Inventory Snapshot Facts
QuantityOnStock - semiadditive
Inventory Process Facts
Conformed Dimensions - as introduced by Kimball
Procurement Transaction Facts
Kinds of Facts
| Transaction | Snapshot | Process | |
|---|---|---|---|
| Grain | One row per event | One row per period | One row per process |
| Fact table loads | Insert | Insert | Insert and update |
| Fact row update | No | No | Yes |
| Date dimension | Transaction date | End-of-period date | Multiple dates |
Example Domains
- Health care
- Telecommunications
- Banking
- Insurance
- Retail
- Manufacturing
- Education
- Government
- Transportation
- Travel
- University