[Lucene-java Wiki] Update of "SearchNumericalFields" by PaulElschot

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The following page has been changed by PaulElschot:
http://wiki.apache.org/lucene-java/SearchNumericalFields

The comment on the change is:
Use indexed instead of stored

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  == NumericRangeQuery (in Lucene Core since version 2.9-dev, which is not yet released) ==
  
- Because Apache Lucene is a full-text search engine and not a conventional database, it cannot handle numerical ranges (e.g., field value is inside user defined bounds, even dates are numerical values). We have developed an extension to Apache Lucene that stores the numerical values in a special string-encoded format with variable precision (called trie, all numerical values like doubles, longs, Dates, floats, and ints are converted to lexicographic sortable string representations and stored with different precisions). A range is then divided recursively into multiple intervals for searching: The center of the range is searched only with the lowest possible precision in the trie, while the boundaries are matched more exactly. This reduces the number of terms dramatically. See: http://hudson.zones.apache.org/hudson/job/Lucene-trunk/javadoc/core/org/apache/lucene/search/NumericRangeQuery.html
+ Because Apache Lucene is a full-text search engine and not a conventional database, it cannot handle numerical ranges (e.g., field value is inside user defined bounds, even dates are numerical values). We have developed an extension to Apache Lucene that stores the numerical values in a special string-encoded format with variable precision (called trie, all numerical values like doubles, longs, Dates, floats, and ints are converted to lexicographic sortable string representations and indexed with different precisions). A range is then divided recursively into multiple intervals for searching: The center of the range is searched only with the lowest possible precision in the trie, while the boundaries are matched more exactly. This reduces the number of terms dramatically. See: http://hudson.zones.apache.org/hudson/job/Lucene-trunk/javadoc/core/org/apache/lucene/search/NumericRangeQuery.html
  
  This dramatically improves the performance of Apache Lucene with range queries, which is no longer dependent on the index size and number of distinct values because there is an upper limit not related to any of these properties.