AFAIK, grouping sets has already been supported for streaming in blink planner. You could check FLINK-12192 for details.
> 在 2019年9月10日，下午6:51，刘建刚 <[hidden email]> 写道：
> I want to implement grouping set in stream. I am new to flink sql. I want to find a example to teach me how to self define rule and implement corresponding operator. Can anyone give me any suggestion?