Aggregating Fact TableTypically, queries require detailed data on some dimensions, while only summary data is needed for the other dimensions
Example: assume one sale per product per store per week. Estimate the number of fact table rows required:
Query involves 1 product, 1 store, 1 week
Query involves 1 product, all stores, 1 week
Query involves 1 brand, 1 store, 1 week
Query involves 1 brand, all stores, 1 year
Suppose now you have an aggregate fact table where each row summarizes the totals for a brand, a store, and a week. Now estimate the number of fact table rows required.