> -----Original Message-----
> From: jim ferenczi <[hidden email]>
> Sent: Thursday, March 14, 2019 1:16 PM
> To: [hidden email]; [hidden email]; java-
> [hidden email] > Subject: [ANNOUNCE] Apache Lucene 8.0.0 released
> 14 March 2019, Apache Lucene™ 8.0.0 available
> The Lucene PMC is pleased to announce the release of Apache Lucene 8.0.0.
> 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:
> http://lucene.apache.org/core/mirrors-core-latest-redir.html >
> Lucene 8.0.0 Release Highlights:
> Query execution
> Term queries, phrase queries and boolean queries introduced new
> optimization that enables efficient skipping over non-competitive documents
> when the total hit count is not needed. Depending on the exact query and
> data distribution, queries might run between a few percents slower and
> times faster, especially term queries and pure disjunctions.
> In order to support this enhancement, some API changes have been made:
> * TopDocs.totalHits is no longer a long but an object that gives a lower
> bound of the actual hit count.
> * IndexSearcher's search and searchAfter methods now only compute total
> hit counts accurately up to 1,000 in order to enable this optimization by
> * Queries are now required to produce non-negative scores.
> * Postings now index score impacts alongside skip data. This is how term
> queries optimize collection of top hits when hit counts are not needed.
> * Doc values introduced jump tables, so that advancing runs in constant
> time. This is especially helpful on sparse fields.
> * The terms index FST is now loaded off-heap for non-primary-key fields
> using MMapDirectory, reducing heap usage for such fields.
> Custom scoring
> The new FeatureField allows efficient integration of static features such
> as a pagerank into the score. Furthermore, the new
> LongPoint#newDistanceFeatureQuery and
> methods allow boosting by recency and geo-distance respectively. These new
> helpers are optimized for the case when total hit counts are not needed.
> For instance if the pagerank has a significant weight in your scores, then
> Lucene might be able to skip over documents that have a low pagerank
> Further details of changes are available in the change log available at:
> http://lucene.apache.org/core/8_0_0/changes/Changes.html >
> Please report any feedback to the mailing lists (
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