- java.lang.Object
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- org.apache.lucene.search.Query
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- org.apache.lucene.search.AbstractKnnVectorQuery
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- Direct Known Subclasses:
KnnByteVectorQuery
,KnnFloatVectorQuery
abstract class AbstractKnnVectorQuery extends Query
UsesKnnVectorsReader.search(java.lang.String, float[], org.apache.lucene.search.KnnCollector, org.apache.lucene.util.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
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Nested Class Summary
Nested Classes Modifier and Type Class Description (package private) static class
AbstractKnnVectorQuery.DocAndScoreQuery
Caches the results of a KnnVector search: a list of docs and their scores
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Constructor Summary
Constructors Constructor Description AbstractKnnVectorQuery(java.lang.String field, int k, Query filter)
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract TopDocs
approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit)
private BitSet
createBitSet(DocIdSetIterator iterator, Bits liveDocs, int maxDoc)
private Query
createRewrittenQuery(IndexReader reader, TopDocs topK)
(package private) abstract VectorScorer
createVectorScorer(LeafReaderContext context, FieldInfo fi)
boolean
equals(java.lang.Object o)
Override and implement query instance equivalence properly in a subclass.protected TopDocs
exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator)
(package private) static int[]
findSegmentStarts(IndexReader reader, int[] docs)
java.lang.String
getField()
Query
getFilter()
int
getK()
private TopDocs
getLeafResults(LeafReaderContext ctx, Weight filterWeight)
int
hashCode()
Override and implement query hash code properly in a subclass.protected TopDocs
mergeLeafResults(TopDocs[] perLeafResults)
Merges all segment-level kNN results to get the index-level kNN results.Query
rewrite(IndexSearcher indexSearcher)
Expert: called to re-write queries into primitive queries.private TopDocs
searchLeaf(LeafReaderContext ctx, Weight filterWeight)
void
visit(QueryVisitor visitor)
Recurse through the query tree, visiting any child queries.-
Methods inherited from class org.apache.lucene.search.Query
classHash, createWeight, rewrite, sameClassAs, toString, toString
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Constructor Detail
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AbstractKnnVectorQuery
public AbstractKnnVectorQuery(java.lang.String field, int k, Query filter)
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Method Detail
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rewrite
public Query rewrite(IndexSearcher indexSearcher) throws java.io.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 classQuery
- Throws:
java.io.IOException
- See Also:
IndexSearcher.rewrite(Query)
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searchLeaf
private TopDocs searchLeaf(LeafReaderContext ctx, Weight filterWeight) throws java.io.IOException
- Throws:
java.io.IOException
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getLeafResults
private TopDocs getLeafResults(LeafReaderContext ctx, Weight filterWeight) throws java.io.IOException
- Throws:
java.io.IOException
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createBitSet
private BitSet createBitSet(DocIdSetIterator iterator, Bits liveDocs, int maxDoc) throws java.io.IOException
- Throws:
java.io.IOException
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approximateSearch
protected abstract TopDocs approximateSearch(LeafReaderContext context, Bits acceptDocs, int visitedLimit) throws java.io.IOException
- Throws:
java.io.IOException
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createVectorScorer
abstract VectorScorer createVectorScorer(LeafReaderContext context, FieldInfo fi) throws java.io.IOException
- Throws:
java.io.IOException
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exactSearch
protected TopDocs exactSearch(LeafReaderContext context, DocIdSetIterator acceptIterator) throws java.io.IOException
- Throws:
java.io.IOException
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mergeLeafResults
protected TopDocs mergeLeafResults(TopDocs[] perLeafResults)
Merges all segment-level kNN results to get the index-level kNN results.The default implementation delegates to
TopDocs.merge(int, TopDocs[])
to find the overall topk
, which requires input results to be sorted.This method is useful for reading and / or modifying the final results as needed.
- Parameters:
perLeafResults
- array of segment-level kNN results.- Returns:
- index-level kNN results (no constraint on their ordering).
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createRewrittenQuery
private Query createRewrittenQuery(IndexReader reader, TopDocs topK)
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findSegmentStarts
static int[] findSegmentStarts(IndexReader reader, int[] docs)
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visit
public void visit(QueryVisitor visitor)
Description copied from class:Query
Recurse through the query tree, visiting any child queries.
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equals
public boolean equals(java.lang.Object o)
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 to those of the other instance. Utility methods are provided for certain repetitive code.
- Specified by:
equals
in classQuery
- See Also:
Query.sameClassAs(Object)
,Query.classHash()
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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.- Specified by:
hashCode
in classQuery
- See Also:
Query.equals(Object)
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getField
public java.lang.String getField()
- Returns:
- the knn vector field where the knn vector search happens.
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getK
public int getK()
- Returns:
- the max number of results the KnnVector search returns.
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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.
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