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https://issues.apache.org/jira/browse/LUCENE-10624?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17558472#comment-17558472
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Adrien Grand commented on LUCENE-10624:
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The code from SearchTaxis.java that you copied doesn't use doc values at all,
it just looks at stored fields, so it shouldn't benefit from your change.
Sorry, maybe your change actually speeds up things, but it's just unclear to me
why and I'd like to make sure that I understand why. :)
bq. I plan to open a new issue for exponential search. Does it make sense?
I'm unsure. my worry is that a naive binary search would make things slower
than the current main branch for many users who have relatively dense fields
that get advanced by small increments.
> Binary Search for Sparse IndexedDISI advanceWithinBlock &
> advanceExactWithinBlock
> ---------------------------------------------------------------------------------
>
> Key: LUCENE-10624
> URL: https://issues.apache.org/jira/browse/LUCENE-10624
> Project: Lucene - Core
> Issue Type: Improvement
> Components: core/codecs
> Affects Versions: 9.0, 9.1, 9.2
> Reporter: Weiming Wu
> Priority: Major
> Attachments: baseline_sparseTaxis_searchsparse-sorted.0.log,
> candiate-exponential-searchsparse-sorted.0.log,
> candidate_sparseTaxis_searchsparse-sorted.0.log
>
> Time Spent: 40m
> Remaining Estimate: 0h
>
> h3. Problem Statement
> We noticed DocValue read performance regression with the iterative API when
> upgrading from Lucene 5 to Lucene 9. Our latency is increased by 50%. The
> degradation is similar to what's described in
> https://issues.apache.org/jira/browse/SOLR-9599
> By analyzing profiling data, we found method "advanceWithinBlock" and
> "advanceExactWithinBlock" for Sparse IndexedDISI is slow in Lucene 9 due to
> their O(N) doc lookup algorithm.
> h3. Changes
> Used binary search algorithm to replace current O(N) lookup algorithm in
> Sparse IndexedDISI "advanceWithinBlock" and "advanceExactWithinBlock" because
> docs are in ascending order.
> h3. Test
> {code:java}
> ./gradlew tidy
> ./gradlew check {code}
> h3. Benchmark
> Ran sparseTaxis test cases from {color:#1d1c1d}luceneutil. Attached the
> reports of baseline and candidates in attachments section.{color}
> {color:#1d1c1d}1. Most cases have 5-10% search latency reduction.{color}
> {color:#1d1c1d}2. Some highlights (>20%):{color}
> * *{color:#1d1c1d}T0 green_pickup_latitude:[40.75 TO 40.9]
> yellow_pickup_latitude:[40.75 TO 40.9] sort=null{color}*
> ** {color:#1d1c1d}*Baseline:* 10973978+ hits hits in *726.81967 msec*{color}
> ** {color:#1d1c1d}*Candidate:* 10973978+ hits hits in *484.544594
> msec*{color}
> * *{color:#1d1c1d}T0 cab_color:y cab_color:g sort=null{color}*
> ** {color:#1d1c1d}*Baseline:* 2300174+ hits hits in *95.698324 msec*{color}
> ** {color:#1d1c1d}*Candidate:* 2300174+ hits hits in *78.336193 msec*{color}
> * {color:#1d1c1d}*T1 cab_color:y cab_color:g sort=null*{color}
> ** {color:#1d1c1d}*Baseline:* 2300174+ hits hits in *391.565239 msec*{color}
> ** {color:#1d1c1d}*Candidate:* 300174+ hits hits in *227.592885
> msec*{color}{*}{*}
> * {color:#1d1c1d}*...*{color}
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