Package org.apache.druid.query.rowsandcols.semantic

Interface FramedOnHeapAggregatable

All Known Implementing Classes:
DefaultFramedOnHeapAggregatable
public interface FramedOnHeapAggregatable
A semantic interface used to aggregate a list of AggregatorFactories across a given set of data

The aggregation specifically happens on-heap and should be used in places where it is known that the data set can be worked with entirely on-heap. There is support for frame definitions, frames aggregate certain subsets of rows in a rolling fashion like a windowed average. Frames are defined in terms of boundaries where a boundary could be based on rows or it could be based on "PEER" groupings.

A peer grouping is defined as a set of rows that are the same based on the ORDER BY columns specified. As such peer-grouped values must also come with a set of ORDER BY columns.

  • Method Details

    • fromRAC

      static FramedOnHeapAggregatable fromRAC(RowsAndColumns rac)

    • aggregateAll

      @Nonnull RowsAndColumns aggregateAll(WindowFrame frame, AggregatorFactory[] aggFactories)
      Aggregates the data according to the WindowFrame using the AggregatorFactory objects provided.
      Parameters:
      frame - window frame definition
      aggFactories - definition of aggregations to be done
      Returns:
      a RowsAndColumns that contains columns representing the results of the aggregation from the AggregatorFactories