Aggregation rule operators

For custom measures, aggregation rule operators perform the equivalent of specifying aggregation rules. The entire BQL expression is enclosed using an aggregate rule operator.

This table shows aggregation examples:

Example	Aggregation
SUM aggregation:	SUM([Order_Date: Sum: Quantity]*2)
AVG aggregation:	AVG([Order_Date: Sum: Quantity]*2)

If an aggregate operator is not specified, then SUM is the default aggregation.