You can also merge all three types into an nary-Either type and union all three inputs together. However, Flink only supports a binary Either, so you'd have to implement a custom TypeInformation and TypeSerializer to make that work.
Best, Fabian 2018-04-26 20:44 GMT+02:00 Chengzhi Zhao <w.zhaocheng...@gmail.com>: > Thanks Fabian for the explanation. > > If I have data with different schemas, it seems the only option I have is > to use connect to perform joins (inner, outer), is there any operators that > can put more than two streams together (all different schema)? > > Best, > Chengzhi > > On Thu, Apr 26, 2018 at 6:05 AM, Fabian Hueske <fhue...@gmail.com> wrote: > >> Hi Chengzhi, >> >> Functions in Flink are implemented in a way to preserve the timestamps of >> elements or assign timestamps which are aligned with the existing >> watermarks. >> For example, the result of a time window aggregation has the end >> timestamp of the window as a timestamp and records emitted by the onTimer() >> method have the timestamp of the timer as a record timestamp. >> So unless you fiddle with internal APIs to reset the record timestamps of >> elements, you don't need to worry about generating new watermarks. >> >> Best, Fabian >> >> 2018-04-25 20:20 GMT+02:00 Chengzhi Zhao <w.zhaocheng...@gmail.com>: >> >>> Hi, everyone, >>> >>> I am trying to do some join-like pipeline using flink connect operator >>> and CoProcessFunction, I have use case that I need to connect 3+ streams. >>> So I am having something like this: >>> >>> A >>> ===> C >>> B ==> E >>> D >>> >>> So two streams A and B connect at first with 3 hours late on low >>> watermark, after data has been emitted (the output C stream), a new stream >>> D connect to C and emitted E as final output. I was wondering how the >>> downstream watermark should be defined. Should I give C stream a new >>> watermark for 3 hours delay again? or when I connect stream D, everything >>> will be 6 hours late on low watermark. >>> >>> I am using BoundedOutOfOrdernessGenerator[1] with maxOutOfOrderness 3 >>> hours >>> >>> Thanks for your tips and help in advance. >>> >>> Best, >>> Chengzhi >>> >>> [1]https://ci.apache.org/projects/flink/flink-docs-release-1 >>> .4/dev/event_timestamps_watermarks.html#with-periodic-watermarks >>> >> >> >
