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From "Fabian Hueske (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-4832) Count/Sum 0 elements
Date Wed, 09 Nov 2016 21:02:58 GMT

    [ https://issues.apache.org/jira/browse/FLINK-4832?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15652028#comment-15652028
] 

Fabian Hueske commented on FLINK-4832:
--------------------------------------

It is true that Flink does not support {{null}} fields in record types, i.e., Flink's Java
Tuples and Scala's Tuples.
However, the {{Row}} type used for aggregations does support {{null}} fields. 

Have a look at how the {{DataSetValues}} class creates a {{DataSet<Row>}} for a given
set of row values.
This technique and the {{ValuesInputFormat}} can be used to create a DataSet with a single
row with all fields being {{null}}.

> 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.



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