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https://issues.apache.org/jira/browse/LUCENE-3130?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13055040#comment-13055040
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Jan Høydahl commented on LUCENE-3130:
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The feature is absolutely needed. Probably it's enough to be able to specify a
global term boost factor per query for all synonyms, so Robert's method would
work for me.
Another usecase is Phonetic variants. Currently I use a separate field for
phonetic normalization and include it with a lower weight in DisMax. If
phonetic variant instead was stored alongside the original with posIncr=0 and
tokenType=phonetic, I could instead specify a deboost factor for phonetic terms
and even highlighting would work ootb!
Yet another is lower/upper case search. If the LowerCaseFilter would keep the
original token and add a lowercased token on same posIncr with
tokenType=lowercase, we could support case insensitive match with preference
for correct case.
If user needs different boost for different fields, perhaps the TokenType name
could be configurable on each filter.
> Use BoostAttribute in in TokenFilters to denote Terms that QueryParser should
> give lower boosts
> -----------------------------------------------------------------------------------------------
>
> Key: LUCENE-3130
> URL: https://issues.apache.org/jira/browse/LUCENE-3130
> Project: Lucene - Java
> Issue Type: Improvement
> Reporter: Hoss Man
>
> A recent thread asked if there was anyway to use QueryTime synonyms such that
> matches on the original term specified by the user would score higher then
> matches on the synonym. It occurred to me later that a float Attribute could
> be set by the SynonymFilter in such situations, and QueryParser could use
> that float as a boost in the resulting Query. IThis would be fairly
> straightforward for the simple "synonyms => BooleamQuery" case, but we'd have
> to decide how to handle the case of synonyms with multiple terms that produce
> MTPQ, possibly just punt for now)
> Likewise, there may be other TokenFilters that "inject" artificial tokens at
> query time where it also might make sense to have a reduced "boost" factor...
> * SynonymFilter
> * CommonGramsFilter
> * WordDelimiterFilter
> * etc...
> In all of these cases, the amount of the "boost" could me configured, and for
> back compact could default to "1.0" (or null to not set a boost at all)
> Furthermore: if we add a new BoostAttrToPayloadAttrFilter that just copied
> the boost attribute into the payload attribute, these same filters could give
> "penalizing" payloads to terms when used at index time) could give
> "penalizing" payloads to terms.
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