Initiates a Cross transformation.
A Cross transformation combines the elements of two
DataSet into one DataSet. It builds all pair combinations of elements of
both DataSets, i.e., it builds a Cartesian product.
This method also gives the hint to the optimizer that the second DataSet to cross is much
smaller than the first one.
The resulting
DefaultCross wraps each pair of crossed elements into a
Tuple2, with
the element of the first input being the first field of the tuple and the element of the
second input being the second field of the tuple.
Call
DefaultCross.with(CrossFunction) to define a
CrossFunction which is called for
each pair of crossed elements. The CrossFunction returns a exactly one element for each pair of input elements.