Difference between map() and flatMap() transformations in Spark
| map() transformation | flatMap() transformation |
|---|---|
| Transforms each input element into | Transforms each input element into |
| a single output element | Zero or more output elements |
| Produces a one-to-one mapping | Produces a one-to-many mapping |
| Retains the original structure of the RDD | Flattens the output by removing any intermediate layers |
| Useful for simple transformations and | Useful for transformations that require |
| aggregations | exploding or splitting elements |
