[
https://issues.apache.org/jira/browse/LUCENE-6229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14329069#comment-14329069
]
Terry Smith commented on LUCENE-6229:
-------------------------------------
I’ll summarize this as two options:
# Remove getChildren() as it complicates the code hurting the ability to
maintain it and make performance enhancements.
# Make getChildren() a more well defined API that gives you the ability to
retrieve child scorers that are correctly positioned.
You are looking for data to backup option 2 to determine if this is an API that
is worth fixing/keeping.
Here are the use cases that I have:
# Custom scoring of a BooleanQuery. A query that wraps any BooleanQuery which
it uses for recall but supplies it’s own scoring algorithm to aggregate the
scores from the original clauses.
# Custom DrillSidewaysQuery. A query that can use the sideways scorers for
precision instead of just recall.
# Recursive DrillSidewaysQuery (not implemented, tricky). A query that could
perform DrillSideways for union or in a nested fashion.
# Auxillary metadata. An enhancement that can augment the current recall
(boolean match) and precision (float score) for a document in the search
pipeline to add extra information that can be used from Query and FunctionValue
instances (collected via a custom Collector) and supported by a custom
SortField.
These can be categorized into two camps:
# Using an existing Query (typically BooleanQuery) to find matches but
providing some combination of
## custom scoring that isn’t compatible with the Similarity API.
## custom recall (think DrillSideways)
# Adding extra information to the search pipeline that can be
## generated by leaf queries and value sources
## aggregated by composing queries (BooleanQuery, DisjunctionMaxQuery, etc)
## survive wrapping queries and value sources that don’t know about it
## collected and sorted on
Hope this helps.
> Remove Scorer.getChildren?
> --------------------------
>
> Key: LUCENE-6229
> URL: https://issues.apache.org/jira/browse/LUCENE-6229
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Adrien Grand
> Priority: Minor
>
> This API is used in a single place in our code base:
> ToParentBlockJoinCollector. In addition, the usage is a bit buggy given that
> using this API from a collector only works if setScorer is called with an
> actual Scorer (and not eg. FakeScorer or BooleanScorer like you would get in
> disjunctions) so it needs a custom IndexSearcher that does not use the
> BulkScorer API.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
