Package org.apache.lucene.search
Class KnnVectorQuery
java.lang.Object
org.apache.lucene.search.Query
org.apache.lucene.search.KnnVectorQuery
Uses
KnnVectorsReader.search(java.lang.String, float[], int, org.apache.lucene.util.Bits, int)
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
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Nested Class Summary
Nested ClassesModifier and TypeClassDescription(package private) static class
Caches the results of a KnnVector search: a list of docs and their scores -
Field Summary
Fields -
Constructor Summary
ConstructorsConstructorDescriptionKnnVectorQuery
(String field, float[] target, int k) Find thek
nearest documents to the target vector according to the vectors in the given field.KnnVectorQuery
(String field, float[] target, int k, Query filter) Find thek
nearest documents to the target vector according to the vectors in the given field. -
Method Summary
Modifier and TypeMethodDescriptionprivate TopDocs
approximateSearch
(LeafReaderContext context, Bits acceptDocs, int visitedLimit) private BitSet
createBitSet
(DocIdSetIterator iterator, Bits liveDocs, int maxDoc) private Query
createRewrittenQuery
(IndexReader reader, TopDocs topK) boolean
Override and implement query instance equivalence properly in a subclass.protected TopDocs
exactSearch
(LeafReaderContext context, DocIdSetIterator acceptIterator) private int[]
findSegmentStarts
(IndexReader reader, int[] docs) int
hashCode()
Override and implement query hash code properly in a subclass.rewrite
(IndexReader reader) Expert: called to re-write queries into primitive queries.private TopDocs
searchLeaf
(LeafReaderContext ctx, Weight filterWeight) Prints a query to a string, withfield
assumed to be the default field and omitted.void
visit
(QueryVisitor visitor) Recurse through the query tree, visiting any child queriesMethods inherited from class org.apache.lucene.search.Query
classHash, createWeight, sameClassAs, toString
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Field Details
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NO_RESULTS
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field
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target
private final float[] target -
k
private final int k -
filter
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Constructor Details
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KnnVectorQuery
Find thek
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 aKnnVectorField
.target
- the target of the searchk
- the number of documents to find- Throws:
IllegalArgumentException
- ifk
is less than 1
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KnnVectorQuery
Find thek
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 aKnnVectorField
.target
- the target of the searchk
- the number of documents to findfilter
- a filter applied before the vector search- Throws:
IllegalArgumentException
- ifk
is less than 1
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Method Details
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rewrite
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.- Overrides:
rewrite
in classQuery
- Throws:
IOException
- See Also:
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searchLeaf
- Throws:
IOException
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createBitSet
private BitSet createBitSet(DocIdSetIterator iterator, Bits liveDocs, int maxDoc) throws IOException - Throws:
IOException
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approximateSearch
private TopDocs approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit) throws IOException - Throws:
IOException
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exactSearch
protected TopDocs exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator) throws IOException - Throws:
IOException
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createRewrittenQuery
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findSegmentStarts
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toString
Description copied from class:Query
Prints a query to a string, withfield
assumed to be the default field and omitted. -
visit
Description copied from class:Query
Recurse through the query tree, visiting any child queries -
equals
Description copied from class:Query
Override and implement query instance equivalence properly in a subclass. This is required so thatQueryCache
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 that other instance. Utility methods are provided for certain repetitive code.
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hashCode
public int hashCode()Description copied from class:Query
Override and implement query hash code properly in a subclass. This is required so thatQueryCache
works properly.
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