Module org.cojen.tupl
Package org.cojen.tupl

Interface Aggregator.Factory<R,T>

Enclosing interface:
Aggregator<R,T>
public static interface Aggregator.Factory<R,T>
Is called to generate a new Aggregator instance for every query against the target table.

  • Method Details

    • newAggregator

      Aggregator<R,T> newAggregator() throws IOException
      Throws:
      IOException

    • sourceProjection

      default String sourceProjection()
      Returns a comma-separated list of source columns which are needed by the Aggregator instances. Null is returned by default, which indicates that all columns are needed. The implementation of this method must return a static constant.

    • plan

      default QueryPlan plan(QueryPlan.Aggregator plan)
      Override this method to customize the aggregator's query plan.
      Parameters:
      plan - original plan
      Returns:
      original or replacement plan