We have seen that changing from a sequential stream to a parallel stream can lead to incorrect results if the code was not written and tested for processing a parallel stream. The following are a few more considerations related to parallel streams.
Parallel streams
Stateless and stateful operations
There are stateless operations, such as filter(), map(), and flatMap(), which do not keep data around (do not maintain state) while moving from processing from one stream element to the next. And there are stateful operations, such as distinct(), limit(), sorted(), reduce(), and collect(), that can pass the state from previously processed elements to the processing of the next element.
Stateless operations usually do not pose a...
