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ASF subversion and git services commented on LUCENE-5207: --------------------------------------------------------- Commit 1523324 from [~thetaphi] in branch 'dev/branches/lucene5207' [ https://svn.apache.org/r1523324 ] LUCENE-5207: Remove useless check > lucene expressions module > ------------------------- > > Key: LUCENE-5207 > URL: https://issues.apache.org/jira/browse/LUCENE-5207 > Project: Lucene - Core > Issue Type: New Feature > Reporter: Ryan Ernst > Attachments: LUCENE-5207.patch > > > Expressions are geared at defining an alternative ranking function (e.g. > incorporating the text relevance score and other field values/ranking > signals). So they are conceptually much more like ElasticSearch's scripting > support (http://www.elasticsearch.org/guide/reference/modules/scripting/) > than solr's function queries. > Some additional notes: > * In addition to referring to other fields, they can also refer to other > expressions, so they can be used as "computed fields". > * You can rank documents easily by multiple expressions (its a SortField at > the end), e.g. Sort by year descending, then some function of score price and > time ascending. > * The provided javascript expression syntax is much more efficient than using > a scripting engine, because it does not have dynamic typing (compiles to > .class files that work on doubles). Performance is similar to writing a > custom FieldComparator yourself, but much easier to do. > * We have solr integration to contribute in the future, but this is just the > standalone lucene part as a start. Since lucene has no schema, it includes an > implementation of Bindings (SimpleBindings) that maps variable names to > SortField's or other expressions. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org