[jira] [Commented] (FLINK-1112) Add GroupSorting with KeySelectors

["ASF GitHub Bot (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-1112?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14229899#comment-14229899 ] 

ASF GitHub Bot commented on FLINK-1112:
---------------------------------------

Github user fhueske commented on a diff in the pull request:

    https://github.com/apache/incubator-flink/pull/209#discussion_r21094436
  
    --- Diff: flink-java/src/main/java/org/apache/flink/api/java/operators/UnsortedGrouping.java ---
    @@ -230,5 +231,21 @@ public UnsortedGrouping(DataSet<T> set, Keys<T> keys) {
     	public SortedGrouping<T> sortGroup(String field, Order order) {
     		return new SortedGrouping<T>(this.dataSet, this.keys, field, order);
     	}
    +
    +	/**
    +	 * Sorts Pojos or Tuple within a group with specified {@link org.apache.flink.api.java.functions.KeySelector} in the specified {@link Order}.</br>
    --- End diff --
    
    The JavaDoc documentation needs some work, IMO.
    KeySelectors are not restricted to Pojos and Tuples. They can extract a key from any data type.
    I would phrase it as: "Sorts elements within a group on a key extracted by the specified KeySelector in the specified order."
    
    The `@param order` refers to a field which has not been mentioned before. Should be the key extracted by the KeySelector.


> Add GroupSorting with KeySelectors
> ----------------------------------
>
>                 Key: FLINK-1112
>                 URL: https://issues.apache.org/jira/browse/FLINK-1112
>             Project: Flink
>          Issue Type: Improvement
>          Components: Java API, Scala API
>            Reporter: Fabian Hueske
>            Assignee: Mingliang Qi
>
> Group sorting is currently only supported for field-index keys and not for KeySelectors.
> This feature was requested.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)