Etienne Chauchot created FLINK-22587: ----------------------------------------
Summary: Support aggregations in batch mode with DataStream API Key: FLINK-22587 URL: https://issues.apache.org/jira/browse/FLINK-22587 Project: Flink Issue Type: Improvement Components: API / DataStream Reporter: Etienne Chauchot A pipeline like this *in batch mode* would output no data {code:java} stream.join(otherStream) .where(<KeySelector>) .equalTo(<KeySelector>) .window(GlobalWindows.create()) .apply(<JoinFunction>) {code} Indeed the default trigger for GlobalWindow is NeverTrigger which never fires. If we set a _EventTimeTrigger_ it will fire with every element as the watermark will be set to +INF (batch mode) and will pass the end of the global window with each new element. A _ProcessingTimeTrigger_ never fires either and all elapsed time or delta based triggers would not be suited for batch. Same goes for _reduce()_ instead of join(). So I guess we miss something for batch support with DataStream. -- This message was sent by Atlassian Jira (v8.3.4#803005)