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Star Schema

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A star schema organizes your model into one central fact table (sales) surrounded by dimension tables. It's the simplest, most performant shape for analytic reporting in Power BI.

Fact (many rows): sales
Dimensions (unique keys): dates, products, customers, stores

This setup allows us to answer questions like:

"What were the total sales for each product in a given month?"
"How many customers bought products in a specific store?"
"What was the average sale amount for each customer in a given year?"

Facts = "what happened" (sales)

Dimensions = "about what" (by product, date, customer, store, etc)

Assignment

Import the following CSVs (Get Data → Text/CSV):
- dates.csv
- products.csv
- stores.csv
Check the data in the Table view to ensure everything imported properly.
Open the "Model View" – it's below "Report" and "Table" views on the left hand side.
Drag the boxes so that products, customers, stores, and dates (dimension tables) are all the spokes of the star. The sales (fact) table should be in the middle. The website_sessions should be off to the side, connected to both stores and customers.

The sales and website_sessions tables should have lines connecting to the other tables automatically. Power BI is smart enough to recognize the ID columns. If it doesn't, you can add relationships manually by dragging the ID column from one table to the matching ID column in another table.

Save the project and, from the course directory, submit the CLI tests.