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https://issues.apache.org/jira/browse/HIVE-22411?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16971777#comment-16971777
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Ashutosh Chauhan commented on HIVE-22411:
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+1
> Performance degradation on single row inserts
> ---------------------------------------------
>
> Key: HIVE-22411
> URL: https://issues.apache.org/jira/browse/HIVE-22411
> Project: Hive
> Issue Type: Bug
> Components: Hive
> Reporter: Attila Magyar
> Assignee: Attila Magyar
> Priority: Major
> Fix For: 4.0.0
>
> Attachments: HIVE-22411.2.patch, HIVE-22411.3.patch, Screen Shot
> 2019-10-17 at 8.40.50 PM.png
>
>
> Executing single insert statements on a transactional table effects write
> performance on a s3 file system. Each insert creates a new delta directory.
> After each insert hive calculates statistics like number of file in the table
> and total size of the table. In order to calculate these, it traverses the
> directory recursively. During the recursion for each path a separate
> listStatus call is executed. In the end the more delta directory you have the
> more time it takes to calculate the statistics.
> Therefore insertion time goes up linearly:
> !Screen Shot 2019-10-17 at 8.40.50 PM.png|width=601,height=436!
> The fix is to use fs.listFiles(path, /**recursive**/ true) instead the
> handcrafter recursive method/
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