Grouping by binning and sorting with ranks

Often, we want to provide descriptive information in our data, based on values that are derived from downstream activities. For example, this could arise if we wish to include a field in the Customer table that shows the value of the previous sales for that customer or a bin grouping that defines the customer into banded sales. This value can then be used to rank each customer according to their relative importance in relation to other customers.

This type of value adding activity is usually troublesome and time intensive in a traditional data mart design as the customer data can be fully updated only once the sales data has been loaded. While this process may seem relatively straightforward, it is a recursive problem as the customer data must be loaded before the sales data (since customers must exist before the sales can be assigned to them), but the full view of the customer is reliant on loading the sales data. In a standard dimensional (star...