Change the granularity of a query

Power BI has excellent data aggregation capabilities, but often you want to pre-aggregate data in Power Query before exposing it to business users. For example, suppose you retrieve data from a system that tracks individual debits and credits from an accounting system: you could aggregate these individual operations up to the daily grain to make it easier to spot patterns and to keep files sizes smaller. In this exercise, you'll aggregate on the average amount of number of employees per year and per geographic ID.

If you have lost any progress, close any open reports and load 2_2_change_granularity.pbix from the Exercises folder on the desktop.