it is possible to split aggregation into parts that use commutative operators. for example global AVG can be expressed as SUM()/COUNT() although AVG is not co

it is possible to split aggregation into parts that use commutative operators. for example global AVG can be expressed as SUM()/COUNT() although AVG is not commutative, SUM() and COUNT() are commutative and can be run in scatter/gather mode and offloaded to individual nodes