Module org.apache.lucene.join

Package org.apache.lucene.search.join

Class DiversifyingChildrenByteKnnVectorQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.AbstractKnnVectorQuery

org.apache.lucene.search.KnnByteVectorQuery

org.apache.lucene.search.join.DiversifyingChildrenByteKnnVectorQuery

public class DiversifyingChildrenByteKnnVectorQuery
extends KnnByteVectorQuery

kNN byte vector query that joins matching children vector documents with their parent doc id. The top documents returned are the child document ids and the calculated scores. Here is how to use this in conjunction with ToParentBlockJoinQuery.

   Query knnQuery = new DiversifyingChildrenByteKnnVectorQuery(fieldName, queryVector, ...);
   // Rewrite executes kNN search and collects nearest children docIds and their scores
   Query rewrittenKnnQuery = searcher.rewrite(knnQuery);
   // Join the scored children docs with their parents and score the parents
   Query childrenToParents = new ToParentBlockJoinQuery(rewrittenKnnQuery, parentsFilter, ScoreMode.MAX);
 

Field Summary

Fields

Modifier and Type	Field	Description
private final Query	childFilter
private final int	k
private static final TopDocs	NO_RESULTS
private final BitSetProducer	parentsFilter
private final byte[]	query

Fields inherited from class org.apache.lucene.search.AbstractKnnVectorQuery

field

Constructor Summary

Constructors

Constructor	Description
DiversifyingChildrenByteKnnVectorQuery(String field, byte[] query, Query childFilter, int k, BitSetProducer parentsFilter)	Create a ToParentBlockJoinByteVectorQuery.

Method Summary

Modifier and Type	Method	Description
protected TopDocs	approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit, KnnCollectorManager knnCollectorManager)
boolean	equals(Object o)	Override and implement query instance equivalence properly in a subclass.
protected TopDocs	exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator, QueryTimeout queryTimeout)
protected KnnCollectorManager	getKnnCollectorManager(int k, IndexSearcher searcher)
int	hashCode()	Override and implement query hash code properly in a subclass.
String	toString(String field)	Prints a query to a string, with field assumed to be the default field and omitted.

Methods inherited from class org.apache.lucene.search.KnnByteVectorQuery

getTargetCopy

Methods inherited from class org.apache.lucene.search.AbstractKnnVectorQuery

getField, getFilter, getK, mergeLeafResults, rewrite, visit

Methods inherited from class org.apache.lucene.search.Query

classHash, createWeight, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

NO_RESULTS

private static final TopDocs NO_RESULTS

parentsFilter

private final BitSetProducer parentsFilter

childFilter

private final Query childFilter

k

private final int k

query

private final byte[] query

Constructor Details

DiversifyingChildrenByteKnnVectorQuery

public DiversifyingChildrenByteKnnVectorQuery(String field,
 byte[] query,
 Query childFilter,
 int k,
 BitSetProducer parentsFilter)

Create a ToParentBlockJoinByteVectorQuery.

Parameters:

field - the query field

query - the vector query

childFilter - the child filter

k - how many parent documents to return given the matching children

parentsFilter - Filter identifying the parent documents.

Method Details

exactSearch

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

Overrides:

exactSearch in class AbstractKnnVectorQuery

Throws:

IOException

getKnnCollectorManager

protected KnnCollectorManager getKnnCollectorManager(int k,
 IndexSearcher searcher)

Overrides:

getKnnCollectorManager in class AbstractKnnVectorQuery

approximateSearch

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

Overrides:

approximateSearch in class KnnByteVectorQuery

Throws:

IOException

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.

Overrides:

toString in class KnnByteVectorQuery

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.

Overrides:

equals in class KnnByteVectorQuery

See Also:

• Query.sameClassAs(Object)
• Query.classHash()

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.

Overrides:

hashCode in class KnnByteVectorQuery

See Also:

• Query.equals(Object)