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https://issues.apache.org/jira/browse/HIVE-16166?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15928899#comment-15928899
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Sergio Peña commented on HIVE-16166:
------------------------------------

I was looking into HIVE-15058 to see if those flaky tests were already 
reported, but they're not. I will retry HiveQA again to see if those flaky 
tests go away. I know these might not related to the patch, but seems we have 
green tests, I would like to give it another shot just to see a clean test 
result.

> HS2 may still waste up to 15% of memory on duplicate strings
> ------------------------------------------------------------
>
>                 Key: HIVE-16166
>                 URL: https://issues.apache.org/jira/browse/HIVE-16166
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Misha Dmitriev
>            Assignee: Misha Dmitriev
>         Attachments: ch_2_excerpt.txt, HIVE-16166.01.patch
>
>
> A heap dump obtained from one of our users shows that 15% of memory is wasted 
> on duplicate strings, despite the recent optimizations that I made. The 
> problematic strings just come from different sources this time. See the 
> excerpt from the jxray (www.jxray.com) analysis attached.
> Adding String.intern() calls in the appropriate places reduces the overhead 
> of duplicate strings with this workload to ~6%. The remaining duplicates come 
> mostly from JDK internal and MapReduce data structures, and thus are more 
> difficult to fix.



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