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Fabian Hueske commented on FLINK-4557: -------------------------------------- Hi [~sunjincheng121], I think your last two comment should go into FLINK-5803 and FLINK-5804, right? Can you move them and delete them here? Thanks, Fabian > Table API Stream Aggregations > ----------------------------- > > Key: FLINK-4557 > URL: https://issues.apache.org/jira/browse/FLINK-4557 > Project: Flink > Issue Type: New Feature > Components: Table API & SQL > Reporter: Timo Walther > > The Table API is a declarative API to define queries on static and streaming > tables. So far, only projection, selection, and union are supported > operations on streaming tables. > This issue and the corresponding FLIP proposes to add support for different > types of aggregations on top of streaming tables. In particular, we seek to > support: > *Group-window aggregates*, i.e., aggregates which are computed for a group of > elements. A (time or row-count) window is required to bound the infinite > input stream into a finite group. > *Row-window aggregates*, i.e., aggregates which are computed for each row, > based on a window (range) of preceding and succeeding rows. > Each type of aggregate shall be supported on keyed/grouped or > non-keyed/grouped data streams for streaming tables as well as batch tables. > Since time-windowed aggregates will be the first operation that require the > definition of time, we also need to discuss how the Table API handles time > characteristics, timestamps, and watermarks. > The FLIP can be found here: > https://cwiki.apache.org/confluence/display/FLINK/FLIP-11%3A+Table+API+Stream+Aggregations -- This message was sent by Atlassian JIRA (v6.3.15#6346)