[jira] [Commented] (LUCENE-9269) Blended queries with boolean rewrite can result in inconsistent scores

["Michael Sokolov (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LUCENE-9269?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17520560#comment-17520560 ] 

Michael Sokolov commented on LUCENE-9269:
-----------------------------------------

# Does the checkBoosts test case you refer to fail when you attempt your change? If so, please address it. Otherwise, I think it should be fixed separately
 # It's OK for two different queries to behave the same, and I don't see how you can know that they will in this case, so they should compare different I think
 # again, toString() is not guaranteed to be different for different queries; I think it's OK

> Blended queries with boolean rewrite can result in inconsistent scores
> ----------------------------------------------------------------------
>
>                 Key: LUCENE-9269
>                 URL: https://issues.apache.org/jira/browse/LUCENE-9269
>             Project: Lucene - Core
>          Issue Type: Bug
>          Components: core/search
>    Affects Versions: 8.4
>            Reporter: Michele Palmia
>            Priority: Minor
>         Attachments: LUCENE-9269-test.patch
>
>
> If two blended queries are should clauses of a boolean query and are built so that
>  * some of their terms are the same
>  * their rewrite method is BlendedTermQuery.BOOLEAN_REWRITE
> the docFreq for the overlapping terms used for scoring is picked as follow:
>  # if the overlapping terms are not boosted, the df of the term in the first blended query is used
>  # if any of the overlapping terms is boosted, the df is picked at (what looks like) random.
> A few examples using a field with 2 terms: f:a (df: 2), and f:b (df: 3).
> {code:java}
> a)
> Blended(f:a f:b) Blended (f:a)
>         df: 3             df: 2
> gets rewritten to:
> (f:a)^2.0 (f:b)
> df: 3      df:2
> b)
> Blended(f:a) Blended(f:a f:b)
>         df: 2        df: 3
> gets rewritten to:
> (f:a)^2.0 (f:b)
>  df: 2     df:2
> c)
> Blended(f:a f:b^0.66) Blended (f:a^0.75)
>         df: 3                  df: 2
> gets rewritten to:
> (f:a)^1.75 (f:b)^0.66
>  df:?       df:2
> {code}
> with ? either 2 or 3, depending on the run.
>  



--
This message was sent by Atlassian Jira
(v8.20.1#820001)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org