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ASF GitHub Bot commented on FLINK-4832: --------------------------------------- Github user fhueske commented on a diff in the pull request: https://github.com/apache/flink/pull/2840#discussion_r88977919 --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/plan/nodes/dataset/DataSetAggregate.scala --- @@ -157,4 +161,41 @@ class DataSetAggregate( case _ => result } } + + /** + * Dummy [[Row]] into a [[DataSet]] for result after map operations. + * @param mapOperator after which insert dummy records + * @param tableEnv [[BatchTableEnvironment]] for getting rel builder and type factory + * @tparam IN mapOperator input type + * @tparam OUT mapOperator output type + * @return DataSet of type Row is contains null literals for columns + */ + private def dummyRow[IN,OUT]( --- End diff -- I would not call this "Dummy row" but "Null row". Dummy row sounds like a useless mock up, but our null row has a good purpose. > Count/Sum 0 elements > -------------------- > > Key: FLINK-4832 > URL: https://issues.apache.org/jira/browse/FLINK-4832 > Project: Flink > Issue Type: Improvement > Components: Table API & SQL > Reporter: Timo Walther > Assignee: Anton Mushin > > Currently, the Table API is unable to count or sum up 0 elements. We should > improve DataSet aggregations for this. Maybe by union the original DataSet > with a dummy record or by using a MapPartition function. Coming up with a > good design for this is also part of this issue. -- This message was sent by Atlassian JIRA (v6.3.4#6332)