The transforms that summarise a set of values into a single result, as opposed to the scalar
transforms, which are applied value by value and propagate the cardinality of their input. An expression carries at
most one of them, and its presence puts the enclosing collection under grouped semantics; see Criteria for
how constraints partition across the grouping.
Aggregate transform.
The transforms that summarise a set of values into a single result, as opposed to the scalar transforms, which are applied value by value and propagate the cardinality of their input. An expression carries at most one of them, and its presence puts the enclosing collection under grouped semantics; see Criteria for how constraints partition across the grouping.