[jira] [Commented] (SPARK-4570) Add broadcast join to left semi join

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

    [ https://issues.apache.org/jira/browse/SPARK-4570?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14224025#comment-14224025 ] 

Apache Spark commented on SPARK-4570:
-------------------------------------

User 'wangxiaojing' has created a pull request for this issue:
https://github.com/apache/spark/pull/3442

> Add broadcast  join to left semi join
> -------------------------------------
>
>                 Key: SPARK-4570
>                 URL: https://issues.apache.org/jira/browse/SPARK-4570
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 1.1.0
>            Reporter: XiaoJing wang
>            Priority: Minor
>             Fix For: 1.1.0
>
>
> For now, spark use broadcast join instead of hash join to optimize {{inner join}} when the size of one side data did not reach the {{AUTO_BROADCASTJOIN_THRESHOLD}}
> However,Spark SQL will perform shuffle operations on each child relations while executing {{left semi join}}  is more suitable for optimiztion with broadcast join. 
> We are planning to create a{{BroadcastLeftSemiJoinHash}} to implement the broadcast join for {{left semi join}}



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

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org