[LUCENE-1360] A Similarity class which has unique length norms for numTerms <= 10

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Component/s: core/query/scoring
• Lucene Fields: New
• Assignee: Otis Gospodnetic
• Reporter: Sean Timm
• Created: 21/Aug/08 19:31
• Updated: 28/Aug/22 11:52
• Resolved: 19/Sep/18 13:42

Description

A Similarity class which extends DefaultSimilarity and simply overrides lengthNorm. lengthNorm is implemented as a lookup for numTerms <= 10, else as 1/sqrt(numTerms). This is to avoid term counts below 11 from having the same lengthNorm after stored as a single byte in the index.

This is useful if your search is only on short fields such as titles or product descriptions.

See mailing list discussion: http://www.nabble.com/How-to-boost-the-score-higher-in-case-user-query-matches-entire-field-value-than-just-some-words-within-a-field-td19079221.html

Issue Links

• is superceded by: LUCENE-7730 Better encode length normalization in similarities