Module org.apache.lucene.core

Package org.apache.lucene.search

Class KnnByteVectorQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.AbstractKnnVectorQuery

org.apache.lucene.search.KnnByteVectorQuery

Direct Known Subclasses:

DiversifyingChildrenByteKnnVectorQuery

public class KnnByteVectorQuery
extends AbstractKnnVectorQuery

Uses KnnVectorsReader.search(String, byte[], KnnCollector, Bits) to perform nearest neighbour search.

This query also allows for performing a kNN search subject to a filter. In this case, it first executes the filter for each leaf, then chooses a strategy dynamically:

• If the filter cost is less than k, just execute an exact search
• Otherwise run a kNN search subject to the filter
• If the kNN search visits too many vectors without completing, stop and run an exact search

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.AbstractKnnVectorQuery

AbstractKnnVectorQuery.DocAndScoreQuery

Field Summary

Fields

Modifier and Type	Field	Description
private static final TopDocs	NO_RESULTS
private final byte[]	target

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

field, k

Constructor Summary

Constructors

Constructor	Description
KnnByteVectorQuery(String field, byte[] target, int k)	Find the k nearest documents to the target vector according to the vectors in the given field.
KnnByteVectorQuery(String field, byte[] target, int k, Query filter)	Find the k nearest documents to the target vector according to the vectors in the given field.

Method Summary

Modifier and Type	Method	Description
protected TopDocs	approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit, KnnCollectorManager knnCollectorManager)
(package private) VectorScorer	createVectorScorer(LeafReaderContext context, FieldInfo fi)
boolean	equals(Object o)	Override and implement query instance equivalence properly in a subclass.
byte[]	getTargetCopy()
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.AbstractKnnVectorQuery

exactSearch, findSegmentStarts, getField, getFilter, getK, getKnnCollectorManager, 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

target

private final byte[] target

Constructor Details

KnnByteVectorQuery

public KnnByteVectorQuery(String field,
 byte[] target,
 int k)

Find the k nearest documents to the target vector according to the vectors in the given field. target vector.

Parameters:

field - a field that has been indexed as a KnnFloatVectorField.

target - the target of the search

k - the number of documents to find

Throws:

IllegalArgumentException - if k is less than 1

KnnByteVectorQuery

public KnnByteVectorQuery(String field,
 byte[] target,
 int k,
 Query filter)

Find the k nearest documents to the target vector according to the vectors in the given field. target vector.

Parameters:

field - a field that has been indexed as a KnnFloatVectorField.

target - the target of the search

k - the number of documents to find

filter - a filter applied before the vector search

Throws:

IllegalArgumentException - if k is less than 1

Method Details

approximateSearch

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

Specified by:

approximateSearch in class AbstractKnnVectorQuery

Throws:

IOException

createVectorScorer

VectorScorer createVectorScorer(LeafReaderContext context,
 FieldInfo fi)
                         throws IOException

Specified by:

createVectorScorer in class AbstractKnnVectorQuery

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.

Specified by:

toString in class Query

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 AbstractKnnVectorQuery

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 AbstractKnnVectorQuery

See Also:

• Query.equals(Object)

getTargetCopy

public byte[] getTargetCopy()

Returns:

the target query vector of the search. Each vector element is a byte.