The Aggr function

The output of the Aggr function can be likened to the list of values a straight table would display when evaluating an expression over a certain dimension. For instance, the following straight table has the Flight Type field as the dimension and Sum([# Departures Performed]) as the expression.

Essentially, the Aggr function creates a virtual straight table, similar to the earlier one, so that we can further process the list of values that would appear in the expression column, without even creating the actual object. The result of the Aggr function can be used to:

• Create a calculated dimension and perform a nested aggregation

• Perform additional aggregations based on the resulting set of values

Let's see examples for both of these.

Using Aggr for nested aggregation

Since HighCloud Airlines' users are interested in discovering key players in the industry from different perspectives, they now require a visualization object that clearly identifies carrier coverage of interstate...