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https://issues.apache.org/jira/browse/KUDU-2866?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Adar Dembo resolved KUDU-2866.
------------------------------
Resolution: Fixed
Fix Version/s: 1.11.0
Fixed in [this
commit|https://github.com/apache/kudu/commit/86cf87686ad1165a18a284a99e2bda5b75de4a20].
> CFileSet::Iterator::FinishBatch takes a lot of CPU for selective wide table
> scans
> ---------------------------------------------------------------------------------
>
> Key: KUDU-2866
> URL: https://issues.apache.org/jira/browse/KUDU-2866
> Project: Kudu
> Issue Type: Improvement
> Components: perf, tablet
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Priority: Major
> Fix For: 1.11.0
>
>
> Scanning a wide table with a predicate that doesn't ever match showed ~10%
> CPU usage in CFileSet::Iterator::FinishBatch. Looking at the assembly it
> seems that the cost was in iterating over the vector<bool> indicating which
> columns had been prepared. In the case of a selective predicate, only one of
> the 200+ columns was prepared, and the iteration was quite slow. Instead of
> using the bitmap, we can instead just keep a list of the prepared column
> iterators.
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