:: Experimental ::
A base class for user-defined aggregations, which can be used in
Dataset operations to take
all of the elements of a group and reduce them to a single value.
The input type for the aggregation.
The type of the intermediate value of the reduction.
The type of the final output result.
Row representing a mutable aggregation buffer.
The base class for implementing user-defined aggregate functions (UDAF).
A user-defined function.
The user-defined functions must be deterministic. Due to optimization, duplicate invocations may be eliminated or the function may even be invoked more times than it is present in the query.
Utility functions for defining window in DataFrames.
A window specification that defines the partitioning, ordering, and frame boundaries.