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https://issues.apache.org/jira/browse/KUDU-646?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Adar Dembo resolved KUDU-646.
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Resolution: Invalid
Fix Version/s: 1.10.0
bq. Adar Dembo is this still relevant after all your changes and optimizations?
It's complicated. After those changes, certain runs of the selection vector may
be all true (if we merged row-by-row) or not (if we merged block-by-block). So
I don't think this optimization is available anymore.
> Check the scan type before applying the selection vector
> --------------------------------------------------------
>
> Key: KUDU-646
> URL: https://issues.apache.org/jira/browse/KUDU-646
> Project: Kudu
> Issue Type: Improvement
> Components: perf, tablet
> Affects Versions: M5
> Reporter: Andrew Wang
> Priority: Trivial
> Fix For: 1.10.0
>
>
> As pointed out during code review of the MergeIterator, after merging the
> selection vector is all true (all rows selected).
> This means during a scan, if we are using the MergeIterator, we can skip
> checking the resulting SelectionVector. This will save us some CPU.
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