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https://issues.apache.org/jira/browse/MAHOUT-963?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Sean Owen updated MAHOUT-963:
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Priority: Minor (was: Major)
Fix Version/s: (was: 0.6)
Issue Type: Improvement (was: Bug)
My profiling shows that the sorting barely registers as part of the time taken
to load a model -- do you have a case where it seems to make a measurable
difference?
These arrays are so small that any sort isn't a problem that I can see.
Still, small wins are wins. I tried a little test, sorting a bunch of these
arrays, where the size is exponentially distributed. The comb sort gets faster
when the average size is about 15 or more, which is realistic for a lot of data
sets. I can squeeze a little more out of the implementation to make it a little
faster.
I think it's a positive change and will put it in after the code freeze.
> GenericUserPreferenceArray and GenericItemPreferenceArray use selection sorts
> -----------------------------------------------------------------------------
>
> Key: MAHOUT-963
> URL: https://issues.apache.org/jira/browse/MAHOUT-963
> Project: Mahout
> Issue Type: Improvement
> Components: Collaborative Filtering
> Affects Versions: 0.6
> Reporter: Bryce Nyeggen
> Assignee: Sean Owen
> Priority: Minor
> Attachments: MAHOUT-963.diff
>
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> Both PreferenceArray implementations use selection sorts with poor
> performance. These sorts are invoked during construction of
> GenericDataModels, causing excessive construction time.
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