Class Rescorer

  • Direct Known Subclasses:
    QueryRescorer, SortRescorer

    public abstract class Rescorer
    extends Object
    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 Detail

      • Rescorer

        public Rescorer()
    • Method Detail

      • rescore

        public abstract TopDocs rescore​(IndexSearcher searcher,
                                        TopDocs firstPassTopDocs,
                                        int topN)
                                 throws IOException
        Rescore an initial first-pass TopDocs.
        searcher - IndexSearcher used to produce the first pass topDocs
        firstPassTopDocs - 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