Package org.apache.lucene.search
Class Rescorer
java.lang.Object
org.apache.lucene.search.Rescorer
- Direct Known Subclasses:
QueryRescorer
,SortRescorer
Re-scores the topN results (
TopDocs
) from an original query. See QueryRescorer
for an actual implementation. Typically, you run a low-cost first-pass query across the entire
index, collecting the top few hundred hits perhaps, and then use this class to mix in a more
costly second pass scoring.
See QueryRescorer.rescore(IndexSearcher,TopDocs,Query,double,int)
for a simple static
method to call to rescore using a 2nd pass Query
.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
-
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionabstract Explanation
explain
(IndexSearcher searcher, Explanation firstPassExplanation, int docID) Explains how the score for the specified document was computed.abstract TopDocs
rescore
(IndexSearcher searcher, TopDocs firstPassTopDocs, int topN) Rescore an initial first-passTopDocs
.
-
Constructor Details
-
Rescorer
public Rescorer()
-
-
Method Details
-
rescore
public abstract TopDocs rescore(IndexSearcher searcher, TopDocs firstPassTopDocs, int topN) throws IOException Rescore an initial first-passTopDocs
.- Parameters:
searcher
-IndexSearcher
used to produce the first pass topDocsfirstPassTopDocs
- Hits from the first pass search. It's very important that these hits were produced by the provided searcher; otherwise the doc IDs will not match!topN
- How many re-scored hits to return- Throws:
IOException
-
explain
public abstract Explanation explain(IndexSearcher searcher, Explanation firstPassExplanation, int docID) throws IOException Explains how the score for the specified document was computed.- Throws:
IOException
-