Package org.apache.lucene.search

Class SeededKnnVectorQuery

java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.SeededKnnVectorQuery
public class SeededKnnVectorQuery extends Query
This is a version of knn vector query that provides a query seed to initiate the vector search. NOTE: The underlying format is free to ignore the provided seed

See "Lexically-Accelerated Dense Retrieval" (Kulkarni, Hrishikesh and MacAvaney, Sean and Goharian, Nazli and Frieder, Ophir). In SIGIR '23: Proceedings of the 46th International ACM SIGIR Conference on Research and Development in Information Retrieval Pages 152 - 162

WARNING: This API is experimental and might change in incompatible ways in the next release.

  • Field Details

    • field

      protected final String field

    • k

      protected final int k

    • filter

      protected final Query filter

    • searchStrategy

      protected final KnnSearchStrategy searchStrategy

  • Method Details

    • fromFloatQuery

      public static SeededKnnVectorQuery fromFloatQuery(KnnFloatVectorQuery knnQuery, Query seed)
      Construct a new SeededKnnVectorQuery instance for a float vector field
      Parameters:
      knnQuery - the knn query to be seeded
      seed - a query seed to initiate the vector format search
      Returns:
      a new SeededKnnVectorQuery instance
      WARNING: This API is experimental and might change in incompatible ways in the next release.

    • fromByteQuery

      public static SeededKnnVectorQuery fromByteQuery(KnnByteVectorQuery knnQuery, Query seed)
      Construct a new SeededKnnVectorQuery instance for a byte vector field
      Parameters:
      knnQuery - the knn query to be seeded
      seed - a query seed to initiate the vector format search
      Returns:
      a new SeededKnnVectorQuery instance
      WARNING: This API is experimental and might change in incompatible ways in the next release.

    • toString

      public String toString(String field)
      Description copied from class: Query
      Prints a query to a string, with field assumed to be the default field and omitted.
      Specified by:
      toString in class Query

    • rewrite

      public Query rewrite(IndexSearcher indexSearcher) throws IOException
      Description copied from class: Query
      Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

      Callers are expected to call rewrite multiple times if necessary, until the rewritten query is the same as the original query.

      The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.

      Throws:
      IOException
      See Also:

    • approximateSearch

      protected TopDocs approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit, KnnCollectorManager knnCollectorManager) throws IOException
      Throws:
      IOException

    • getKnnCollectorManager

      protected KnnCollectorManager getKnnCollectorManager(int k, IndexSearcher searcher)

    • exactSearch

      protected TopDocs exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator, QueryTimeout queryTimeout) throws IOException
      Throws:
      IOException

    • mergeLeafResults

      protected TopDocs mergeLeafResults(TopDocs[] perLeafResults)
      Merges all segment-level kNN results to get the index-level kNN results.

      The default implementation delegates to TopDocs.merge(int, TopDocs[]) to find the overall top k, which requires input results to be sorted.

      This method is useful for reading and / or modifying the final results as needed.

      Parameters:
      perLeafResults - array of segment-level kNN results.
      Returns:
      index-level kNN results (no constraint on their ordering).

    • visit

      public void visit(QueryVisitor visitor)
      Description copied from class: Query
      Recurse through the query tree, visiting any child queries.
      Parameters:
      visitor - a QueryVisitor to be called by each query in the tree

    • equals

      public boolean equals(Object o)
      Description copied from class: Query
      Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly.

      Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.

      See Also:

    • hashCode

      public int hashCode()
      Description copied from class: Query
      Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.
      See Also:

    • getField

      public String getField()
      Returns:
      the knn vector field where the knn vector search happens.

    • getK

      public int getK()
      Returns:
      the max number of results the KnnVector search returns.

    • getFilter

      public Query getFilter()
      Returns:
      the filter that is executed before the KnnVector search happens. Only the results accepted by this filter are returned by the KnnVector search.