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https://issues.apache.org/jira/browse/LUCENE-2205?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13104976#comment-13104976
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Doug Cutting commented on LUCENE-2205:
--------------------------------------

A few comments on the patch:
 - It'd probably be better not to make TermInfosReaderIndex and its subclasses 
public, to reduce the APIs that must be supported long-term.
 - Could you use BufferedIndexInput directly instead of re-implementing 
readVInt, readVLong, etc?
 - The code uses tabs for indentation.  Lucene's standard is 2-spaces per 
level, no tabs. http://wiki.apache.org/lucene-java/HowToContribute
 - It would be good to add some tests, perhaps running some existing set of 
test searches with a reader  configured to use the new TermInfosReaderIndex 
implementation.

Probably the "Fix-version" of this patch should be 3.5, since it's not fixing a 
regression.

> 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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