Maybe you are all right. I was more confused . As the cwiki said, flink could use BoundedOutOfOrderTimestamps , [image: image.png]
but I have heard about WatermarkAssignerOperator from Blink developers. Benchao Li <libenc...@gmail.com> 于2020年4月17日周五 下午4:33写道： > Hi lec ssmi, > > It's a good question. In blink planner, we use code gen to handle > watermark expression. > And in `WatermarkAssignerOperator` we calculate current watermark when > each element comes in. > If the watermark - lastEmitedWatermark > watermark interval, we will emit > the new watermark. > > So it's neither `PeriodicWatermark` nor `PunctuatedWatermark`. > > lec ssmi <shicheng31...@gmail.com> 于2020年4月17日周五 下午3:12写道： > >> Hi: >> In sql API , the declaration of watermark is realized by ddl statement >> . But which way is it implemented? >> * PeriodicWatermark * or *PunctuatedWatermark*？ >> There seems to be no explanation on the official website. >> >> Thanks. >> > > > -- > > Benchao Li > School of Electronics Engineering and Computer Science, Peking University > Tel:+86-15650713730 > Email: libenc...@gmail.com; libenc...@pku.edu.cn > >
