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https://issues.apache.org/jira/browse/LUCENE-10225?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17445045#comment-17445045
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Bruno Roustant commented on LUCENE-10225:
-----------------------------------------
I'm a bit confused. I put this change in the 9.1 section in CHANGES, but
actually should it be in the 9.0 section [~jpountz]?
> Improve IntroSelector with 3-way partitioning
> ---------------------------------------------
>
> Key: LUCENE-10225
> URL: https://issues.apache.org/jira/browse/LUCENE-10225
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Bruno Roustant
> Priority: Major
> Time Spent: 3h 20m
> Remaining Estimate: 0h
>
> The same way we improved IntroSorter, we can improve IntroSelector with
> Bentley-McIlroy 3-way partitioning. The gain in performance is roughly the
> same.
> With this new approach, we always use medians-of-medians (Tukey's Ninther),
> so there is no real gain to fallback to a slower medians-of-medians technique
> as an introspective protection (like the existing implementation does).
> Instead we can simply shuffle the sub-range if we exceed the recursive max
> depth (this does not change the speed as this intro-protective mechanism
> almost never happens - maybe only in adversarial cases).
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