Hi, there are basically two operations to merge streams.
1. Union simply merges the input streams such that the resulting stream has the records of all input streams. Union is a built-in operator in the DataStream API. For that all streams must have the same data type. 2. Join connects records of streams according to a join condition. When joining streams, this condition is often based on some time bounds. Join usually needs to be manually implemented using a stateful CoProcessFunction. Once the streams are unioned or joined, you can apply a time-window on the result stream. Best, Fabian 2017-07-19 9:05 GMT+02:00 Jone Zhang <joyoungzh...@gmail.com>: > I have three data streams > 1. app exposed and click > 2. app download > 3. app install > > How can i merge the streams to create a unified stream,then compute it on > time-based windows > > Thanks >