# Dimensional Modeling (DM)

* Easy to use, write queries quickly and effectively
* Fast data retrieval
* Historical data
* **Dimensions** give the context (who, where, when, what)
* **Facts** are measurements and metrics

## Fact and Dimension

### Fact Table

* Include numerical values (Amount, Quantity)
* Include foreign Keys to associated dimension tables

### Dimension Table

* Descriptive characteristics of the facts
* Join to fact table via a foreign key
* Denormalized tables
* Use a surrogate key
* Store the history

## Dimensional and 3NF

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