[ 
https://issues.apache.org/jira/browse/LUCENE-4574?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Robert Muir updated LUCENE-4574:
--------------------------------

    Attachment: LUCENE-4574.patch

this is getting a little complicated.

here's an alternative patch (I just hacked it up quickly).

in the case where you have relevance comparator and also track 
scores/maxScores, we just return a "ScoresTwiceCollector".

I think this approach might be less dangerous, so we don't break common cases 
for a special case.

Something to think about: your test passes (I didnt even run other tests)

                
> FunctionQuery ValueSource value computed twice per document
> -----------------------------------------------------------
>
>                 Key: LUCENE-4574
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4574
>             Project: Lucene - Core
>          Issue Type: Bug
>          Components: core/search
>    Affects Versions: 4.0, 4.1
>            Reporter: David Smiley
>            Assignee: David Smiley
>         Attachments: LUCENE-4574.patch, LUCENE-4574.patch, LUCENE-4574.patch, 
> LUCENE-4574.patch, Test_for_LUCENE-4574.patch
>
>
> I was working on a custom ValueSource and did some basic profiling and 
> debugging to see if it was being used optimally.  To my surprise, the value 
> was being fetched twice per document in a row.  This computation isn't 
> exactly cheap to calculate so this is a big problem.  I was able to 
> work-around this problem trivially on my end by caching the last value with 
> corresponding docid in my FunctionValues implementation.
> Here is an excerpt of the code path to the first execution:
> {noformat}
>         at 
> org.apache.lucene.queries.function.docvalues.DoubleDocValues.floatVal(DoubleDocValues.java:48)
>         at 
> org.apache.lucene.queries.function.FunctionQuery$AllScorer.score(FunctionQuery.java:153)
>         at 
> org.apache.lucene.search.TopFieldCollector$OneComparatorScoringMaxScoreCollector.collect(TopFieldCollector.java:291)
>         at org.apache.lucene.search.Scorer.score(Scorer.java:62)
>         at 
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:588)
>         at 
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:280)
> {noformat}
> And here is the 2nd call:
> {noformat}
>         at 
> org.apache.lucene.queries.function.docvalues.DoubleDocValues.floatVal(DoubleDocValues.java:48)
>         at 
> org.apache.lucene.queries.function.FunctionQuery$AllScorer.score(FunctionQuery.java:153)
>         at 
> org.apache.lucene.search.ScoreCachingWrappingScorer.score(ScoreCachingWrappingScorer.java:56)
>         at 
> org.apache.lucene.search.FieldComparator$RelevanceComparator.copy(FieldComparator.java:951)
>         at 
> org.apache.lucene.search.TopFieldCollector$OneComparatorScoringMaxScoreCollector.collect(TopFieldCollector.java:312)
>         at org.apache.lucene.search.Scorer.score(Scorer.java:62)
>         at 
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:588)
>         at 
> org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:280)
> {noformat}
> The 2nd call appears to use some score caching mechanism, which is all well 
> and good, but that same mechanism wasn't used in the first call so there's no 
> cached value to retrieve.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to