Class AggregateExpression

Direct Known Subclasses:
AggregateListExpression, CompilableAggregateExpression, FirstValExpression

public abstract class AggregateExpression extends Expression
Expressions containing aggregates are computed in two phases: phase 1: the input tuples are passed to a list of expressions composed by the group by columns and the list of aggregates phase 2: the output tuples of phase 1 are passed to the list of original select list. In this phase, aggregates act as a ColumnExpression