Title: Apache Lucene 4.8.0 Available category: core/news URL: save_as:
The Lucene PMC is pleased to announce the release of Apache Lucene 4.8.0
Apache Lucene is a high-performance, full-featured text search engine library written entirely in Java. It is a technology suitable for nearly any application that requires full-text search, especially cross-platform.
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/mirrors-core-latest-redir.html
See the CHANGES.txt file included with the release for a full list of details.
Apache Lucene now requires Java 7 or greater (recommended is Oracle Java 7 or OpenJDK 7, minimum update 55; earlier versions have known JVM bugs affecting Lucene).
Apache Lucene is fully compatible with Java 8.
All index files now store end-to-end checksums, which are now validated during merging and reading. This ensures that corruptions caused by any bit-flipping hardware problems or bugs in the JVM can be detected earlier. For full detection be sure to enable all checksums during merging (it's disabled by default).
Lucene has a new Rescorer/QueryRescorer API to perform second-pass rescoring or reranking of search results using more expensive scoring functions after first-pass hit collection.
AnalyzingInfixSuggester now supports near-real-time autosuggest.
Simplified impact-sorted postings (using SortingMergePolicy and EarlyTerminatingCollector) to use Lucene's Sort class to express the sort order.
Bulk scoring and normal iterator-based scoring were separated, so some queries can do bulk scoring more effectively.
Switched to MurmurHash3 to hash terms during indexing.
IndexWriter now supports updating of binary doc value fields.
HunspellStemFilter now uses 10 to 100x less RAM. It also loads all known OpenOffice dictionaries without error.
Lucene now also fsyncs the directory metadata on commits, if the operating system and file system allow it (Linux, MacOSX are known to work).
Lucene now uses Java 7 file system functions under the hood, so index files can be deleted on Windows, even when readers are still open.
A serious bug in NativeFSLockFactory was fixed, which could allow multiple IndexWriters to acquire the same lock. The lock file is no longer deleted from the index directory even when the lock is not held.
Various bugfixes and optimizations since the 4.7.2 release.