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Stemmed Lucene Implementation Details

Search with the Lucene query syntax, using stemmed terms.  A search for 'trees' will get a hit on 'tree'  This requires an extra indexed field when it is enabled in the load.

Algorithm:

The Stemmed Lucene search has the following characteristics:

• This search is case in-sensitive. 
• It searches on the stem property value.  
  
• Parsing is done with our custom stemming analyzer.  This has the following filters:
  • LowerCaseFilter - for setting to lowercase
    
  • StopFilter - to remove stop words (the, a, etc.) from the search
    
  • SnowballFilter - for stemming
    

Example of use:

The following examples are based on the Automobiles coding scheme.

Example 1:

Search string: Automobiles

Lucene query: stem_propertyValue:automobil

Result: 1 result

• entity code: A0001
• entity description: Automobile

Example 2:
Search string: Automobiled

Lucene query: stem_propertyValue:automobil

Result: 1 result

• entity code: A0001
• entity description: Automobile

Associated JUnits:

Junits can be found here: https://github.com/lexevs/lexevs/blob/master/lbTest/src/test/java/org/LexGrid/LexBIG/Impl/function/query/lucene/searchAlgorithms/TestStemming.java