Class KnnVectorsReader
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Accountable
- Direct Known Subclasses:
Lucene91HnswVectorsReader
,PerFieldKnnVectorsFormat.FieldsReader
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Field Summary
Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract void
Checks consistency of this reader.Returns an instance optimized for merging.abstract VectorValues
getVectorValues
(String field) Returns theVectorValues
for the givenfield
.abstract TopDocs
Return the k nearest neighbor documents as determined by comparison of their vector values for this field, to the given vector, by the field's similarity function.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources, ramBytesUsed
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Constructor Details
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KnnVectorsReader
protected KnnVectorsReader()Sole constructor
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Method Details
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checkIntegrity
Checks consistency of this reader.Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.
- Throws:
IOException
- NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.
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getVectorValues
Returns theVectorValues
for the givenfield
. The behavior is undefined if the given field doesn't have KNN vectors enabled on itsFieldInfo
. The return value is nevernull
.- Throws:
IOException
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search
public abstract TopDocs search(String field, float[] target, int k, Bits acceptDocs, int visitedLimit) throws IOException Return the k nearest neighbor documents as determined by comparison of their vector values for this field, to the given vector, by the field's similarity function. The score of each document is derived from the vector similarity in a way that ensures scores are positive and that a larger score corresponds to a higher ranking.The search is allowed to be approximate, meaning the results are not guaranteed to be the true k closest neighbors. For large values of k (for example when k is close to the total number of documents), the search may also retrieve fewer than k documents.
The returned
TopDocs
will contain aScoreDoc
for each nearest neighbor, in order of their similarity to the query vector (decreasing scores). TheTotalHits
contains the number of documents visited during the search. If the search stopped early because it hitvisitedLimit
, it is indicated through the relationTotalHits.Relation.GREATER_THAN_OR_EQUAL_TO
.The behavior is undefined if the given field doesn't have KNN vectors enabled on its
FieldInfo
. The return value is nevernull
.- Parameters:
field
- the vector field to searchtarget
- the vector-valued queryk
- the number of docs to returnacceptDocs
-Bits
that represents the allowed documents to match, ornull
if they are all allowed to match.visitedLimit
- the maximum number of nodes that the search is allowed to visit- Returns:
- the k nearest neighbor documents, along with their (searchStrategy-specific) scores.
- Throws:
IOException
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getMergeInstance
Returns an instance optimized for merging. This instance may only be consumed in the thread that calledgetMergeInstance()
.The default implementation returns
this
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