Hibernate Search Result Ranking

Question

I am using Hibernate Search Along with Lucene to implement full text search on my data base. I want to know that do hibernate search query or lucene query return top ranked and the most relevant results? Documentation says:

Apache Lucene provides a very flexible and powerful way to sort results. While the default sorting (by relevance) is appropriate most of the time

Link: http://docs.jboss.org/hibernate/search/4.2/reference/en-US/html_single/#search-query

Section: 5.1.3.3. Sorting

But I am very confused with the results as they are always arranged with the IDs of the objects. I just need the top 100 most relevant records.

Answer 1

请参阅自定义Lucene的评分公式

Answer 2

Sorting by relevance is affected by your Analyzer choices. If you are getting results in the order of primary keys it is likely that they are all having the same score, which is normally very unlikely so my guess is that you're not enabling tokenization on any searched field.

Make sure you're tokenizing the fields used in the Query and they are using an appropriate Analyzer. To pick an appropriate one you'll have to experiment a bit as it depends on the language (if it's natural language) or on what kind of data you're indexing.

To actually debug the sort order applied by Relevance sort, see usage of Projections in the Hibernate Search documentation: both FullTextQuery.SCORE and FullTextQuery.EXPLANATION can be very useful to understand what's going on.

A handy utility to quickly experiment the effect of different Analyzers is to use org.hibernate.search.util.AnalyzerUtils . You can either write unit tests creating the Analyzer instance yourself or you can retrieve the analyzers by name using org.hibernate.search.engine.SearchFactory.getAnalyzer(String) or the base one used for a specific indexed entity by entity type: org.hibernate.search.engine.SearchFactory.getAnalyzer(Class) .