Package org.apache.spark.sql.connector.catalog.functions

Interface Reducer<I,O>

Type Parameters:

I - reducer input type

O - reducer output type

@Evolving
public interface Reducer<I,O>

A 'reducer' for output of user-defined functions.

Since:

4.0.0

See Also:

• A user defined function f_source(x) is 'reducible' on another user_defined function f_target(x) if
  • There exists a reducer function r(x) such that r(f_source(x)) = f_target(x) for all input x, or
  • More generally, there exists reducer functions r1(x) and r2(x) such that r1(f_source(x)) = r2(f_target(x)) for all input x.

Method Summary

Modifier and Type	Method	Description
O	reduce(I arg)

Method Details

reduce

O reduce(I arg)