[ANNOUNCE] Apache Lucene 9.7.0 released

[Adrien Grand <jp...@gmail.com>]

The Lucene PMC is pleased to announce the release of Apache Lucene 9.7.0.

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 across high-dimensionality vectors, spell
correction or query suggestions.

This release contains numerous bug fixes, 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 9.7.0 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 by NIOFSDirectory and SimpleFSDirectory. 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!

Please read CHANGES.txt for a full list of new features and changes:

  <https://lucene.apache.org/core/9_7_0/changes/Changes.html>

-- 
Adrien