A man goes to see his doctor and says, "Doctor, it hurts when I do this," and the doctor says, "Don't do that." Performance tuning can only go so far as to remedy a problem that might simply be a usability issue. Tabular technology can do impressive things with data, but every technology has its practical limits, and the best solution might be to change the approach or to educate users in ways to have a better experience. We will begin with an example to demonstrate this principle.
Using Excel to browse the Tabular Model created in Chapter 10, DAX Calculations and Queries, you will play the role of a business user. Your objective is to first get the total of year-to-date sales daily and then the customers and the products they purchased. We will typically look at the report at the end of each month, so we'll need to filter the data by year and month.