Interface Aggregator.Factory<R,T>
- Enclosing interface:
Aggregator<R,
T>
public static interface Aggregator.Factory<R,T>
Is used to generate a new
Aggregator
instance for every query against the
target table.-
Method Summary
Modifier and TypeMethodDescriptionAggregator
<R, T> default QueryPlan
plan
(QueryPlan.Aggregator plan) Override this method to customize the aggregator's query plan.default String
Returns a comma-separated list of source columns which are needed by theAggregator
instances.
-
Method Details
-
newAggregator
- Throws:
IOException
-
sourceProjection
Returns a comma-separated list of source columns which are needed by theAggregator
instances. Null is returned by default, which indicates that all columns are needed. The implementation of this method must return a static constant. -
plan
Override this method to customize the aggregator's query plan.- Parameters:
plan
- original plan- Returns:
- original or replacement plan
-