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https://issues.apache.org/jira/browse/HIVE-24710?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17290025#comment-17290025
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Zoltan Haindrich commented on HIVE-24710:
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[~rajesh.balamohan]: this patch seem to have created an interesting situation
in my eclispe - and I don't understand how it even compiles for other people...
the patch change the Range class so its not static anymore - however that class
is used as a member in a static class; I've opened HIVE-24823
> Optimise PTF iteration for count(*) to reduce CPU and IO cost
> -------------------------------------------------------------
>
> Key: HIVE-24710
> URL: https://issues.apache.org/jira/browse/HIVE-24710
> Project: Hive
> Issue Type: Improvement
> Components: HiveServer2
> Reporter: Rajesh Balamohan
> Assignee: Rajesh Balamohan
> Priority: Major
> Labels: performance, pull-request-available
> Fix For: 4.0.0
>
> Time Spent: 40m
> Remaining Estimate: 0h
>
> E.g query
> {noformat}
> select x, y, count(*) over (partition by x order by y range between 86400
> PRECEDING and CURRENT ROW) r0 from foo
> {noformat}
> 1. In such cases, there is no need to iterate over the rowcontainers often
> (internally it does O(n^2) operations taking forever when window frame is
> really large). This can be optimised to reduce CPU burn and IO.
> 2. BasePartitionEvaluator::calcFunctionValue need not materialize ROW when
> parameters are empty. This codepath can also be optimised.
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