[This topic is pre-release documentation and is subject to change in future releases. Blank topics are included as placeholders.]
Base expression node that represents an aggregation function such as 'sum' or 'count'.
In terms of validation each concrete aggregation node must implement it's own validation.
In terms of evaluation this base class will ask the assigned
net.esper.eql.core.AggregationResultFuture
for the current state, using a column number assigned to the node.
Concrete subclasses must supply an aggregation state prototype node net.esper.eql.core.Aggregator
that reflects each group's (there may be group-by critera) current aggregation state.
Protected Fields
Name | Description | |
---|---|---|
![]() | isDistinct |
Indicator for whether the aggregation is distinct - i.e. only unique
values are considered.
|