[jira] [Assigned] (SPARK-40830) Dataset.groupBy.as should be preferred over Dataset.groupByKey

["Apache Spark (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/SPARK-40830?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Apache Spark reassigned SPARK-40830:
------------------------------------

    Assignee:     (was: Apache Spark)

> Dataset.groupBy.as should be preferred over Dataset.groupByKey
> --------------------------------------------------------------
>
>                 Key: SPARK-40830
>                 URL: https://issues.apache.org/jira/browse/SPARK-40830
>             Project: Spark
>          Issue Type: Improvement
>          Components: Documentation, SQL
>    Affects Versions: 3.4.0
>            Reporter: Enrico Minack
>            Priority: Minor
>
> Calling {{Dataset.groupBy(...).as[K, T]}} should be preferred over calling {{Dataset.groupByKey(...)}} whenever possible. The former allows Catalyst to exploit existing partitioning and ordering of the Dataset, while the latter hides from Catalyst which columns are used to create the keys.
> Example:
> Calling {{ds.groupByKey(_.id)}} hides from Catalyst that column id is the grouping key.
> With {{ds.groupBy($"id").as[Int, V]}} tells Catalyst that {{ds}} is to be grouped by (partitioned and ordered by) column "id".
> This fact should be documented. Further, {{groupByKey}} methods with {{Column}} and {{String}} arguments would help to short cut {{groupByKey.as}} and avoid the {{groupBy(func)}} methods.



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