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https://issues.apache.org/jira/browse/HIVE-28196?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17842018#comment-17842018
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Denys Kuzmenko edited comment on HIVE-28196 at 4/29/24 3:04 PM:
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Merged to master.
thanks [~glapark], [~seonggon] for the patch, and [~zhangbutao], [~okumin] for
the review.
[~seonggon] would you mind creating another PR that cherry-picks the fix into
branch-4.0?
was (Author: dkuzmenko):
Merged to master.
thanks [~glapark], [~seonggon] for the patch, and [~zhangbutao] for the review.
[~seonggon] would you mind creating another PR that cherry-picks the fix into
branch-4.0?
> Preserve column stats when applying UDF upper/lower.
> ----------------------------------------------------
>
> Key: HIVE-28196
> URL: https://issues.apache.org/jira/browse/HIVE-28196
> Project: Hive
> Issue Type: Improvement
> Affects Versions: 4.0.0
> Reporter: Seonggon Namgung
> Assignee: Seonggon Namgung
> Priority: Major
> Labels: hive-4.0.1-must, performance, pull-request-available
> Fix For: 4.1.0
>
>
> Current Hive re-estimates column stats (including avgColLen) when it
> encounters UDF.
> In the case of upper and lower, Hive sets avgColLen to
> hive.stats.max.variable.length.
> But these UDFs do not change column stats and the default value(100) is too
> high for string type key columns, on which upper/lower are usually applied.
> This patch keeps input data's avgColLen after applying UDF upper/lower to
> make a better query plan.
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