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 QueryPlanplan(QueryPlan.Aggregator plan) Override this method to customize the aggregator's query plan.default StringReturns a comma-separated list of source columns which are needed by theAggregatorinstances.
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Method Details
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newAggregator
- Throws:
IOException
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sourceProjection
Returns a comma-separated list of source columns which are needed by theAggregatorinstances. 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
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