Similarity.lengthNorm and positionIncrement=0
---------------------------------------------
Key: LUCENE-1420
URL: https://issues.apache.org/jira/browse/LUCENE-1420
Project: Lucene - Java
Issue Type: Improvement
Components: Index
Affects Versions: 2.3.3, 2.9
Reporter: Andrzej Bialecki
Fix For: 2.3.3, 2.9
Calculation of lengthNorm factor should in some cases take into account the
number of tokens with positionIncrement=0. This should be made optional, to
support two different scenarios:
* when analyzers insert artificially constructed tokens into TokenStream (e.g.
ASCII-fied versions of accented terms, stemmed terms), and it's unlikely that
users submit queries containing both versions of tokens: in this case
lengthNorm calculation should ignore the tokens with positionIncrement=0.
* when analyzers insert synonyms, and it's likely that users may submit queries
that contain multiple synonymous terms: in this case the lengthNorm should be
calculated as it is now, i.e. it should take into account all terms no matter
what is their positionIncrement.
The default should be backward-compatible, i.e. it should count all tokens.
(See also the discussion here: http://markmail.org/message/vfvmzrzhr6pya22h )
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
