Community Contributions

Demoting results

The BoostingQuery class can be used to effectively demote results that match a given query. Unlike the "NOT" clause, this still selects documents that contain undesirable terms, but reduces their overall score:

Query balancedQuery = new BoostingQuery(positiveQuery, negativeQuery, 0.01f);

In this scenario the positiveQuery contains the mandatory, desirable criteria which is used to select all matching documents, and the negativeQuery contains the undesirable elements which are simply used to lessen the scores. Documents that match the negativeQuery have their score multiplied by the supplied "boost" parameter, so this should be less than 1 to achieve a demoting effect.

This code was made available here: http://marc.theaimsgroup.com/?l=lucene-user&m=108058407130459&w=2

Utilities

LSql is a command-line tool that allows the user to run sql-like queries against the Lucene index. This tool is useful for automated migrations, because it allows the developer to treat a Lucene index the same as you would a database.

Luke is an absolutely terrific utility for testing your lucene indices and queries dynamically through a GUI.

Extensions

Zoie is a realtime search system built on Lucene.

Bobo is a facet search extension to Lucene.