Denormalization Patterns

There are several standard denormalization patterns, each with specific use cases and tradeoffs. Knowing which pattern fits your situation saves you from reinventing solutions that the industry has already standardized. Pattern 1: Pre-Joined Dimension Columns Copy frequently-queried dimension attributes directly into the fact table. Instead of joining fact_orders to dim_customer to get customer_region, store customer_region on the fact row. This eliminates the JOIN for every query that filters or groups by region. Tradeoff: if a customer changes region, every historical fact row still shows the old region. This may be correct (revenue should be attributed to the region at the time of purchase) or incorrect (customer reports should show current region). Know which case applies. Pattern 2: S