Ian

Star, and the Pro limit is the argument that wins on its own. A flat table repeats every customer name, product description and region string on all 12 million rows. Pull those into dimensions and the fact table keeps integer keys, which compress dramatically better. I have watched that exact change take a dataset from 900MB to 200MB without changing a single visual.

The second benefit is that slicers stop fighting you. On a flat table a product slicer only shows products that had sales in the filtered period, which confuses users constantly. With a dimension table you decide.

Agreed on the principle, but "nobody else builds on the dataset" has a half life of about six months in most companies.

Also check your PodDisruptionBudgets before you drain anything. A budget that cannot be satisfied will stall a drain indefinitely and burn your window while nothing appears to be wrong.