Using CheckpointedFunction interface with Keyed state

[Jayant Ameta]

Hi,

I'm trying to understand the state functionality. Is there any case where using CheckpointedFunction with Keyed state makes any sense?

Or the CheckpointedFunction is only to be used with operator state?

Also, trying to understand the BufferinSink example here: https://ci.apache.org/projects/flink/flink-docs-release-1.5/dev/stream/state/state.html

Does the ListState get checkpointed on its own if it is used inside OperatorState?

Regards,