Package org.apache.lucene.search

Class KnnVectorQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.KnnFloatVectorQuery

org.apache.lucene.search.KnnVectorQuery

@Deprecated
public class KnnVectorQuery
extends KnnFloatVectorQuery

Deprecated.

use KnnFloatVectorQuery instead

Uses KnnVectorsReader.search(String, float[], 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

Field Summary

Fields

Modifier and Type	Field	Description
protected String	field
protected int	k

Constructor Summary

Constructors

Constructor	Description
KnnVectorQuery(String field, float[] target, int k)	Deprecated.
KnnVectorQuery(String field, float[] target, int k, Query filter)	Deprecated.

Method Summary

Modifier and Type	Method	Description
protected TopDocs	exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator)
String	getField()
Query	getFilter()
int	getK()
Query	rewrite(IndexSearcher indexSearcher)	Expert: called to re-write queries into primitive queries.
void	visit(QueryVisitor visitor)	Recurse through the query tree, visiting any child queries.

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

approximateSearch, equals, getTargetCopy, hashCode, toString

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 Detail

field

protected final String field

k

protected final int k

Constructor Detail

KnnVectorQuery

public KnnVectorQuery(String field,
                      float[] target,
                      int k)

Deprecated.

KnnVectorQuery

public KnnVectorQuery(String field,
                      float[] target,
                      int k,
                      Query filter)

Deprecated.

Method Detail

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.

However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.

Overrides:

rewrite in class Query

Throws:

IOException

See Also:

IndexSearcher.rewrite(Query)

exactSearch

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

Throws:

IOException

visit

public void visit(QueryVisitor visitor)

Description copied from class: Query

Recurse through the query tree, visiting any child queries.

Specified by:

visit in class Query

Parameters:

visitor - a QueryVisitor to be called by each query in the tree

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.