?? September 2022, Apache Lucene™ 9.4 available
The Lucene PMC is pleased to announce the release of Apache Lucene 9.4
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 9.4 Release Highlights
New features
- Added ShapeDocValues/Field, a unified abstraction to represent existing types: XY and lat/long.
- FacetSets can now be filtered using a Query via MatchingFacetSetCounts.
- SortField now allows control over whether to apply index-sort optimizations.
Optimizations
Added support for dynamic pruning to queries sorted by a string field that is indexed with both terms and SORTED or SORTED_SET doc values. This can lead to dramatic speedups when applicable.
TermInSetQuery is optimized for the case when one of its terms matches all docs in a segment, and it now provides cost estimation, making it usable with IndexOrDocValuesQuery for better query planning.
- KnnVector fields can now be stored with reduced (8-bit) precision, saving storage and yielding a small query latency improvement.
Other
- KnnVector fields' HNSW graphs are now created incrementally when new documents are added, rather than all-at-once when flushing. This yields more consistent predictable behavior at the cost of an overall increase in indexing time.
- randomizedtesting dependency upgraded to 2.8.1
- addIndexes(CodecReader) now respects MergePolicy and MergeScheduler, enabling it to do its work concurrently.
... 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_4_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.