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https://issues.apache.org/jira/browse/HIVE-11531?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15004738#comment-15004738
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Sergey Shelukhin commented on HIVE-11531:
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It looks like many q.out files changed due to "Offset" being added. In any
case, I think there's no need to output the offset 0, because that is the
implied default for LIMIT. If you return null from the method, the explain
setting will not be output.
The rest looks good to me, except for some spacing inconsistent with the
surrounding file (e.g. ==2 w/o spaces when processing TOK_LIMIT, etc).
[~jcamachorodriguez] can you take a look at Calcite related changes, would this
work with Calcite?
> 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, HIVE-11531.WIP.2.patch,
> HIVE-11531.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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