New Features

Support for similarity-based vector searches, ie. finding all nearest neighbors whose similarity is greater than a configured threshold from a query vector. See [Byte|Float]VectorSimilarityQuery.
Index sorting is now compatible with block joins. See IndexWriterConfig#setParentField.
MMapDirectory now takes advantage of the now finalized JDK foreign memory API internally when running on Java 22 (or later). This was only supported with Java 19 to 21 until now.
SIMD vectorization now takes advantage of JDK vector incubator on Java 22. This was only supported with Java 20 or 21 until now.

Optimizations

Tail postings are now encoded using group-varint. This yielded speedups on queries that match lots of terms that have short postings lists in Lucene's nightly benchmarks.
Range queries on points now exit earlier when evaluating a segment that has no matches. This will improve performance when intersected with other queries that have a high up-front cost such as multi-term queries.
BooleanQueries that mix SHOULD and FILTER clauses now propagate minimum competitive scores to the SHOULD clauses, yielding significant speedups for top-k queries sorted by descending score.
IndexSearcher#count has been optimized on pure disjunctions of two term queries.