25th June 2023, Apache Lucene™ 9.7 available
The Lucene PMC is pleased to announce the release of Apache Lucene 9.7
Apache Lucene is a high-performance, full-featured search engine library written entirely in Java. It is a technology suitable for nearly any application that requires structured search, full-text search, faceting, nearest-neighbor search on high-dimensionality vectors, spell correction or query suggestions.
This release contains numerous features, optimizations, and improvements, some of which are highlighted below. The release is available for immediate download at:
https://lucene.apache.org/core/downloads.html
Lucene 9.7 Release Highlights
New features
- The new IndexWriter#updateDocuments(Query, Iterable) allows updating multiple documents that match a query at the same time.
- Function queries can now compute similarity scores between kNN vectors.
Optimizations
- KNN indexing and querying can now take advantage of vectorization for distance computation between vectors. To enable this, use exactly Java 20 or 21, and pass
--add-modules jdk.incubator.vector
as a command-line parameter to the Java program. KNN queries now run concurrently if the IndexSearcher has been created with an executor.
- Queries sorted by field are now able to dynamically prune hits only using the
after
value. This yields major speedups when paginating deeply. - Reduced merge-time overhead of computing the number of soft deletes.
Changes in runtime behavior
- KNN vectors are now disallowed to have non-finite values such as NaN or ±Infinity.
Bug fixes
- Backward reading is no longer an adversarial case for
BufferedIndexInput
, used byNIOFSDirectory
andSimpleFSDirectory
. This addresses a performance bug when performing terms dictionary lookups with either of these directories. GraphTokenStreamFiniteStrings#articulationPointsRecurse
may no longer overflow the stack.- ... plus a number of helpful bug fixes!
Further details of changes are available in the change log available at: https://lucene.apache.org/core/9_7_0/changes/Changes.html.
Please report any feedback to the mailing lists (http://lucene.apache.org/core/discussion.html)
Note: The Apache Software Foundation now uses a content distribution network (CDN) for distributing releases.