[jira] [Updated] (HIVE-9561) SHUFFLE_SORT should only be used for order by query [Spark Branch]

["Rui Li (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-9561?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Rui Li updated HIVE-9561:
-------------------------
    Attachment: HIVE-9561.1-spark.patch

The patch can only partially solve the problem. For some cases, we still can use SHUFFLE_SORT when we don't have to. For example:
{code}
explain select * from (select pagerank from tiny sort by pagerank) t join (select * from skewed order by pagerank) s on t.pagerank=s.pagerank;
{code}
We have a sort-by and an order-by. However, the patch can't distinguish these two and we'll use SHUFFLE_SORT for both of them.
[~xuefuz] any ideas?

> SHUFFLE_SORT should only be used for order by query [Spark Branch]
> ------------------------------------------------------------------
>
>                 Key: HIVE-9561
>                 URL: https://issues.apache.org/jira/browse/HIVE-9561
>             Project: Hive
>          Issue Type: Sub-task
>          Components: Spark
>            Reporter: Rui Li
>            Assignee: Rui Li
>         Attachments: HIVE-9561.1-spark.patch
>
>
> The {{sortByKey}} shuffle launches probe jobs. Such jobs can hurt performance and are difficult to control. So we should limit the use of {{sortByKey}} to order by query only.



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