OpenSearch Lucene Study Group Meeting - Monday, February 19th, 2024

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Link to previous meeting’s post: OpenSearch Lucene Study Group Meeting - Monday, February 12th, 2024

Welcome to the OpenSearch Lucene Study Group!

Apache Lucene is the open-sourced search library that powers OpenSearch and many search applications large and small.

We start the meeting with a Lucene learning topic or Q&A session. In the second half of the meeting, we review recent developments in Apache Lucene and discuss their potential impact to OpenSearch, with a particular focus on new and exciting Lucene features that we can (and should) expose through OpenSearch. Since some changes require a deep dive to fully understand, we sometimes ask participants to volunteer for “homework” to dig deeper into changes and report back for the next meeting.

Standing Agenda:

  • Welcome / introduction (5 minutes)
  • Lucene learning series - someone will either present a Lucene-related talk or we will do Lucene Q&A (20 minutes, recorded)
  • Review assigned issues from last time (10 minutes)
  • Review new Lucene changes and assign homework (20 minutes)

By joining the OpenSearch Lucene Study Group Meeting, you grant OpenSearch, and our affiliates the right to record, film, photograph, and capture your voice and image during the OpenSearch Community Meeting (the “Recordings”). You grant to us an irrevocable, nonexclusive, perpetual, worldwide, royalty-free right and license to use, reproduce, modify, distribute, and translate, for any purpose, all or any part of the Recordings and Your Materials. For example, we may distribute Recordings or snippets of Recordings via our social media outlets.

Relatively few Lucene changes this week, as folks prepare for the pending 9.10 release (which may be out by the time the meeting starts).

In fact, all of this week’s changes are code clean-ups by Dmitry Cherniachenko.

Lucene 9.11.0Improvements`static final Map` constants have been made immutable
Lucene 9.11.0ImprovementsTokenizedPhraseQueryNode code cleanup
Lucene 9.11.0OtherReplace numerous `brToString(BytesRef)` copies with a `ToStringUtils` method

Rishabh will look into Propagate minimum competitive score in ReqOptSumScorer. by jpountz · Pull Request #13026 · apache/lucene · GitHub to explain it to us next time.


  1. Reviewed draft Lucene 9.10 release notes (expecting release this week): Release notes 9.10 - Apache Lucene (Java) - Apache Software Foundation
  2. Looked over this week’s contributions.
  3. Looked over Lucene GitHub issue search (powered by Lucene):
  4. Looked at Boolean query introduction