[jira] Commented: (HIVE-949) Object deepCopy in GroupBy Operator

["He Yongqiang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-949?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12781750#action_12781750 ] 

He Yongqiang commented on HIVE-949:
-----------------------------------

no problem.

> Object deepCopy in GroupBy Operator
> -----------------------------------
>
>                 Key: HIVE-949
>                 URL: https://issues.apache.org/jira/browse/HIVE-949
>             Project: Hadoop Hive
>          Issue Type: Improvement
>            Reporter: Ning Zhang
>            Assignee: He Yongqiang
>
> In GroupByOperator, objects are first deep copied and then check whether or not the object is in the hash table (in hash-mode aggregation). In fact, object deep copy could be very expensive (around 5% CPU time). A simple change could be generate the object without deep copy through ObjectInspector and check its existence in the hash table. If not exists, we call deep copy. 

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.