Sliding function in spark

Question

Can you please let me know what is the use of the sliding function in spark with a small example? I have read from many sites but didn't get the basic understanding that why we use this function.

Answer 1

The sliding function is used when you want to have windows to be of a length different than what you slide by. Also sliding is more preferable in such a situation rather than grouping. 

The Sliding function results in an RDD from grouping items of its parent RDD in fixed size block by passing window over them. A window operator is defined by two parameters:-

•  WindowDuration - the length of the window
•  SlideDuration - the interval at which the window will slide or move forward

The Signature for the sliding function is as follows:

def sliding(n: Int, step: Int = 1): Repr[immutable.Seq[Out]]