Hi, You would apply a assignTimestampsAndWatermarks() operation on the unioned stream. However, this would not allow you to sort the join by timestamp, since no sorting is supported out-of-box in Flink.
Best, Aljoscha > On 26. Jul 2017, at 21:37, G.S.Vijay Raajaa <gsvijayraa...@gmail.com> wrote: > > HI, > > I am having a union of 3 kafka topic stream, i am joining them by a timestamp > field. I would like to order the join by timestamp. How do I assign a > watermark and extract timestamp from a union stream? > > Regards, > Vijay Raajaa GS