Why should you care?

Running heavy GROUP BY on live Orders blocks shoppers.

See it live — copy this example

Run in SQL Server Management Studio (SSMS) or Azure Data Studio.

USE DataVerse;
SELECT d.TheDate, SUM(d.Revenue) AS Revenue
FROM dbo.FactOrderDaily d
WHERE d.TheDate >= DATEADD(DAY, -7, CAST(SYSUTCDATETIME() AS DATE))
GROUP BY d.TheDate
ORDER BY d.TheDate;
-- ETL idea: INSERT FactOrderDaily SELECT ... FROM OLTP with CDC or nightly job

What happened?

• FactOrderDaily powers a 7-day revenue trend without touching Orders.
• ETL comments remind you facts are loaded, not casually joined forever to OLTP.

Practice next

1. Ensure fact table + CCI exist.
2. Run the 7-day revenue query.
3. Sketch a nightly load from Orders.
4. Break down revenue by ProductId.
5. Add a DimDate table and join it.

Remember

Separate analytics storage. Facts + dimensions + schedules. Protect OLTP from heavy scans.

DataVerse warehouse

Nightly job fills facts; Power BI reads CCI.

Outcome: Exec dashboards never lock checkout tables.