flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-4832) Count/Sum 0 elements
Date Mon, 21 Nov 2016 20:22:59 GMT

    [ https://issues.apache.org/jira/browse/FLINK-4832?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15684615#comment-15684615
] 

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)

Mime
View raw message