Apache Lucene

Apache Lucene 7.4.0 release, Java search engine


Apache Lucene 7.4.0 has been released, Lucene is an open-source full-text search engine toolkit for the Apache Software Foundation, is a full-text search engine architecture that provides a complete query engine and index engine, part of the text analysis engine. Lucene’s goal is to provide an easy-to-use toolkit for software developers to facilitate full-text retrieval in the target system, or to build a complete full-text search engine based on it.


New Features   (19)

  1. LUCENE-8200: Allow doc-values to be updated atomically together with a document. Doc-Values updates now can be used as a soft-delete mechanism to all keeping several version of a document or already deleted documents around for later reuse. See “IW.softUpdateDocument(…)” for reference.
    (Simon Willnauer)
  2. LUCENE-8197: A new FeatureField makes it easy and efficient to integrate static relevance signals into the final score.
    (Adrien Grand, Robert Muir)
  3. LUCENE-8202: Add a FixedShingleFilter
    (Alan Woodward, Adrien Grand, Jim Ferenczi)
  4. LUCENE-8125: ICUTokenizer support for emoji/emoji sequence tokens.
    (Robert Muir)
  5. LUCENE-8196LUCENE-8300: A new IntervalQuery in the sandbox allows efficient proximity searches based on minimum-interval semantics.
    (Alan Woodward, Adrien Grand, Jim Ferenczi, Simon Willnauer, Matt Weber)
  6. LUCENE-8233: Add support for soft deletes to IndexWriter delete accounting. Soft deletes are accounted for inside the index writer and therefor also by merge policies. A SoftDeletesRetentionMergePolicy is added that allows to selectively carry over soft_deleted document across merges for retention policies
    (Simon Willnauer, Mike McCandless, Robert Muir)
  7. LUCENE-8237: Add a SoftDeletesDirectoryReaderWrapper that allows to respect soft deletes if the reader is opened form a directory.
    (Simon Willnauer, Mike McCandless, Uwe Schindler, Adrien Grand)
  8. LUCENE-8229LUCENE-8270: Add a method Weight.matches(LeafReaderContext, doc) that returns an iterator over matching positions for a given query and document. This allows exact hit extraction and will enable implementation of accurate highlighters.
    (Alan Woodward, Adrien Grand, David Smiley)
  9. LUCENE-8249: Implement Matches API for phrase queries
    (Alan Woodward, Adrien Grand)



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