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https://issues.apache.org/jira/browse/LUCENE-2205?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13105554#comment-13105554
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Doug Cutting commented on LUCENE-2205:
--------------------------------------

Michael, thanks for responding.  Great to hear that this is likely greatly 
improved in 4.0!

This patch is a minor refactoring to add an extension point and a new 
implementation of that extension point that's not used by default.  There 
appear to be both refactorings (LUCENE-3201, LUCENE-3360) and new features 
scheduled for 3.5.  Do you feel this refactoring is riskier than those?

It should certainly also be demonstrated that this provides significant 
advantages over termInfosIndexDivisor before it is committed.

> Rework of the TermInfosReader class to remove the Terms[], TermInfos[], and 
> the index pointer long[] and create a more memory efficient data structure.
> -------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: LUCENE-2205
>                 URL: https://issues.apache.org/jira/browse/LUCENE-2205
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: core/index
>         Environment: Java5
>            Reporter: Aaron McCurry
>         Attachments: RandomAccessTest.java, TermInfosReader.java, 
> TermInfosReaderIndex.java, TermInfosReaderIndexDefault.java, 
> TermInfosReaderIndexSmall.java, patch-final.txt, rawoutput.txt
>
>
> Basically packing those three arrays into a byte array with an int array as 
> an index offset.  
> The performance benefits are stagering on my test index (of size 6.2 GB, with 
> ~1,000,000 documents and ~175,000,000 terms), the memory needed to load the 
> terminfos into memory were reduced to 17% of there original size.  From 291.5 
> MB to 49.7 MB.  The random access speed has been made better by 1-2%, load 
> time of the segments are ~40% faster as well, and full GC's on my JVM were 
> made 7 times faster.
> I have already performed the work and am offering this code as a patch.  
> Currently all test in the trunk pass with this new code enabled.  I did write 
> a system property switch to allow for the original implementation to be used 
> as well.
> -Dorg.apache.lucene.index.TermInfosReader=default or small
> I have also written a blog about this patch here is the link.
> http://www.nearinfinity.com/blogs/aaron_mccurry/my_first_lucene_patch.html

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