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https://issues.apache.org/jira/browse/LUCENE-2230?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12833010#action_12833010
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Fuad Efendi commented on LUCENE-2230:
-------------------------------------

LUCENE-2089 - extremely good staff (Lucene-Flex branch, applicable for 
wildcard-queries, RegEx, and Fuzzy Search). BKTree improves performance if 
distance is 2; otherwise it is almost full-term-scan.
Some links borrowed:
http://en.wikipedia.org/wiki/Deterministic_finite-state_machine
http://rcmuir.wordpress.com/2009/12/04/finite-state-queries-for-lucene/
http://www.amazon.com/Algorithms-Strings-Trees-Sequences-Computational/dp/0521585198


> Lucene Fuzzy Search: BK-Tree can improve performance 3-20 times.
> ----------------------------------------------------------------
>
>                 Key: LUCENE-2230
>                 URL: https://issues.apache.org/jira/browse/LUCENE-2230
>             Project: Lucene - Java
>          Issue Type: Improvement
>    Affects Versions: 3.0
>         Environment: Lucene currently uses brute force full-terms scanner and 
> calculates distance for each term. New BKTree structure improves performance 
> in average 20 times when distance is 1, and 3 times when distance is 3. I 
> tested with index size several millions docs, and 250,000 terms. 
> New algo uses integer distances between objects.
>            Reporter: Fuad Efendi
>         Attachments: BKTree.java, Distance.java, DistanceImpl.java, 
> FuzzyTermEnumNEW.java, FuzzyTermEnumNEW.java
>
>   Original Estimate: 0.02h
>  Remaining Estimate: 0.02h
>
> W. Burkhard and R. Keller. Some approaches to best-match file searching, 
> CACM, 1973
> http://portal.acm.org/citation.cfm?doid=362003.362025
> I was inspired by 
> http://blog.notdot.net/2007/4/Damn-Cool-Algorithms-Part-1-BK-Trees (Nick 
> Johnson, Google).
> Additionally, simplified algorythm at 
> http://www.catalysoft.com/articles/StrikeAMatch.html seems to be much more 
> logically correct than Levenstein distance, and it is 3-5 times faster 
> (isolated tests).
> Big list od distance implementations:
> http://www.dcs.shef.ac.uk/~sam/stringmetrics.htm

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