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https://issues.apache.org/jira/browse/HIVE-11531?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Hui Zheng updated HIVE-11531:
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Attachment: HIVE-11531.WIP.1.patch
Hi [~sershe]
To get some opinion from you I uploaded a patch which implemented the
mysql-style LIMIT simply but isn't completely finished.
Next I will implement it with CBO and research how to improve the
Optimizers(GroupByOptimizer and GlobalLimitOptimizer) .At last I will do more
tests.
> Add mysql-style LIMIT support to Hive, or improve ROW_NUMBER performance-wise
> -----------------------------------------------------------------------------
>
> Key: HIVE-11531
> URL: https://issues.apache.org/jira/browse/HIVE-11531
> Project: Hive
> Issue Type: Improvement
> Reporter: Sergey Shelukhin
> Assignee: Hui Zheng
> Attachments: HIVE-11531.WIP.1.patch
>
>
> For any UIs that involve pagination, it is useful to issue queries in the
> form SELECT ... LIMIT X,Y where X,Y are coordinates inside the result to be
> paginated (which can be extremely large by itself). At present, ROW_NUMBER
> can be used to achieve this effect, but optimizations for LIMIT such as TopN
> in ReduceSink do not apply to ROW_NUMBER. We can add first class support for
> "skip" to existing limit, or improve ROW_NUMBER for better performance
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