org.elasticsearch.search.rescore

Interface Rescorer

All Known Implementing Classes:

QueryRescorer

public interface Rescorer

A query rescorer interface used to re-rank the Top-K results of a previously executed search. Subclasses should borrow heavily from QueryRescorer because it is fairly well behaved and documents that tradeoffs that it is making. There is also an ExampleRescorer that is worth looking at.

Method Summary

Modifier and Type	Method and Description
org.apache.lucene.search.Explanation	explain(int topLevelDocId, org.apache.lucene.search.IndexSearcher searcher, RescoreContext rescoreContext, org.apache.lucene.search.Explanation sourceExplanation) Executes an Explanation phase on the rescorer.
void	extractTerms(org.apache.lucene.search.IndexSearcher searcher, RescoreContext rescoreContext, java.util.Set<org.apache.lucene.index.Term> termsSet) Extracts all terms needed to execute this Rescorer.
org.apache.lucene.search.TopDocs	rescore(org.apache.lucene.search.TopDocs topDocs, org.apache.lucene.search.IndexSearcher searcher, RescoreContext rescoreContext) Modifies the result of the previously executed search (TopDocs) in place based on the given RescoreContext.

Method Detail

rescore

org.apache.lucene.search.TopDocs rescore(org.apache.lucene.search.TopDocs topDocs,
                                         org.apache.lucene.search.IndexSearcher searcher,
                                         RescoreContext rescoreContext)
                                  throws java.io.IOException

Modifies the result of the previously executed search (TopDocs) in place based on the given RescoreContext.

Parameters:

topDocs - the result of the previously executed search

searcher - the searcher used for this search. This will never be null.

rescoreContext - the RescoreContext. This will never be null

Throws:

java.io.IOException - if an IOException occurs during rescoring

explain

org.apache.lucene.search.Explanation explain(int topLevelDocId,
                                             org.apache.lucene.search.IndexSearcher searcher,
                                             RescoreContext rescoreContext,
                                             org.apache.lucene.search.Explanation sourceExplanation)
                                      throws java.io.IOException

Executes an Explanation phase on the rescorer.

Parameters:

topLevelDocId - the global / top-level document ID to explain

searcher - the searcher used for this search. This will never be null.

rescoreContext - context for this rescorer

sourceExplanation - explanation of the source of the documents being fed into this rescore

Returns:

the explain for the given top level document ID.

Throws:

java.io.IOException - if an IOException occurs

extractTerms

void extractTerms(org.apache.lucene.search.IndexSearcher searcher,
                  RescoreContext rescoreContext,
                  java.util.Set<org.apache.lucene.index.Term> termsSet)
           throws java.io.IOException

Extracts all terms needed to execute this Rescorer. This method is executed in a distributed frequency collection roundtrip for SearchType.DFS_QUERY_THEN_FETCH

Throws:

java.io.IOException