Package org.elasticsearch.xpack.esql.expression.function.vector

Class Knn

java.lang.Object

org.elasticsearch.xpack.esql.core.tree.Node<Expression>

org.elasticsearch.xpack.esql.core.expression.Expression

org.elasticsearch.xpack.esql.core.expression.function.Function

org.elasticsearch.xpack.esql.expression.function.fulltext.FullTextFunction

org.elasticsearch.xpack.esql.expression.function.fulltext.SingleFieldFullTextFunction

org.elasticsearch.xpack.esql.expression.function.vector.Knn

All Implemented Interfaces:

NamedWriteable, Writeable, PostAnalysisPlanVerificationAware, PostOptimizationPlanVerificationAware, PostOptimizationVerificationAware, RewriteableAware, TranslationAware, Resolvable, EvaluatorMapper, OptionalArgument, VectorFunction, ExpressionScoreMapper

public class Knn
extends SingleFieldFullTextFunction
implements OptionalArgument, VectorFunction, PostOptimizationVerificationAware

Nested Class Summary

Nested classes/interfaces inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

Expression.TypeResolution

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

EvaluatorMapper.ToEvaluator

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.score.ExpressionScoreMapper

ExpressionScoreMapper.ToScorer

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.capabilities.PostOptimizationVerificationAware

PostOptimizationVerificationAware.CoordinatorOnly

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.capabilities.TranslationAware

TranslationAware.FinishedTranslatable, TranslationAware.SingleValueTranslationAware, TranslationAware.Translatable

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

Writeable.Reader<V>, Writeable.Writer<V>

Field Summary

Fields

Modifier and Type	Field	Description
static final Map<String,DataType>	ALLOWED_OPTIONS
static final NamedWriteableRegistry.Entry	ENTRY
static final String	MIN_CANDIDATES_OPTION

Fields inherited from class org.elasticsearch.xpack.esql.expression.function.fulltext.SingleFieldFullTextFunction

field

Fields inherited from class org.elasticsearch.xpack.esql.core.tree.Node

TO_STRING_MAX_WIDTH

Constructor Summary

Constructors

Constructor	Description
Knn(Source source, Expression field, Expression query, Expression options)
Knn(Source source, Expression field, Expression query, Expression options, Integer implicitK, QueryBuilder queryBuilder, List<Expression> filterExpressions)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
protected QueryBuilder	evaluatorQueryBuilder()	Returns the query builder to be used when the function cannot be pushed down to Lucene, but uses a LuceneQueryEvaluator instead
List<Expression>	filterExpressions()
protected Map<String,DataType>	getAllowedOptions()	Returns the allowed options map for this function.
protected Set<DataType>	getFieldDataTypes()	Returns the set of allowed data types for the field parameter.
protected Set<DataType>	getQueryDataTypes()	Returns the set of allowed data types for the query parameter.
String	getWriteableName()
int	hashCode()
Integer	implicitK()
protected NodeInfo<? extends Expression>	info()
void	postOptimizationVerification(Failures failures)	Validates the implementing expression - discovered failures are reported to the given Failures class.
List<Number>	queryAsObject()	Converts the query expression to an Object suitable for the Lucene query.
Expression	replaceChildren(List<Expression> newChildren)
Expression	replaceQueryBuilder(QueryBuilder queryBuilder)	Replaces the current query builder with a rewritten iteration.
TranslationAware.Translatable	translatable(LucenePushdownPredicates pushdownPredicates)	Can this instance be translated or not? Usually checks whether the expression arguments are actual fields that exist in Lucene.
protected Query	translate(LucenePushdownPredicates pushdownPredicates, TranslatorHandler handler)
Expression	withFilters(List<Expression> filterExpressions)
Knn	withImplicitK(Integer k)
void	writeTo(StreamOutput out)

Methods inherited from class org.elasticsearch.xpack.esql.expression.function.fulltext.SingleFieldFullTextFunction

expectedFieldTypesString, expectedQueryTypesString, field, fieldAsFieldAttribute, fold, foldable, nullable, options, postAnalysisPlanVerification, postOptimizationPlanVerification, resolveField, resolveOptions, resolveParams, resolveQuery

Methods inherited from class org.elasticsearch.xpack.esql.expression.function.fulltext.FullTextFunction

asQuery, dataType, fieldAsFieldAttribute, fieldVerifier, functionType, getNameFromFieldAttribute, query, queryBuilder, resolveQuery, resolveType, toEvaluator, toScorer

Methods inherited from class org.elasticsearch.xpack.esql.core.expression.function.Function

arguments, functionName, nodeString

Methods inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

canonical, canonicalize, childrenResolved, propertiesToString, references, resolved, semanticEquals, semanticHash, toString, typeResolved

Methods inherited from class org.elasticsearch.xpack.esql.core.tree.Node

anyMatch, children, collect, collect, collect, collectFirstChildren, collectLeaves, doCollectFirst, forEachDown, forEachDown, forEachDownMayReturnEarly, forEachProperty, forEachPropertyDown, forEachPropertyOnly, forEachPropertyUp, forEachUp, forEachUp, nodeName, nodeProperties, replaceChildrenSameSize, source, sourceLocation, sourceText, transformChildren, transformDown, transformDown, transformDown, transformNodeProps, transformPropertiesDown, transformPropertiesOnly, transformPropertiesUp, transformUp, transformUp, transformUp

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

fold

Methods inherited from interface org.elasticsearch.xpack.esql.capabilities.TranslationAware

asLuceneQuery

Field Details

ENTRY

public static final NamedWriteableRegistry.Entry ENTRY

MIN_CANDIDATES_OPTION

public static final String MIN_CANDIDATES_OPTION

See Also:

• Constant Field Values

ALLOWED_OPTIONS

public static final Map<String,DataType> ALLOWED_OPTIONS

Constructor Details

Knn

public Knn(Source source,
 Expression field,
 Expression query,
 Expression options)

Knn

public Knn(Source source,
 Expression field,
 Expression query,
 Expression options,
 Integer implicitK,
 QueryBuilder queryBuilder,
 List<Expression> filterExpressions)

Method Details

implicitK

public Integer implicitK()

filterExpressions

public List<Expression> filterExpressions()

withImplicitK

public Knn withImplicitK(Integer k)

queryAsObject

public List<Number> queryAsObject()

Description copied from class: SingleFieldFullTextFunction

Converts the query expression to an Object suitable for the Lucene query. Handles common conversions for BytesRef, UNSIGNED_LONG, DATETIME, and DATE_NANOS.

Overrides:

queryAsObject in class SingleFieldFullTextFunction

replaceQueryBuilder

public Expression replaceQueryBuilder(QueryBuilder queryBuilder)

Description copied from interface: RewriteableAware

Replaces the current query builder with a rewritten iteration. This happens multiple times through the rewrite phase until the final iteration of the query builder is stored.

Specified by:

replaceQueryBuilder in interface RewriteableAware

Parameters:

queryBuilder - QueryBuilder

Returns:

Expression defining the active QueryBuilder

translatable

public TranslationAware.Translatable translatable(LucenePushdownPredicates pushdownPredicates)

Description copied from interface: TranslationAware

Can this instance be translated or not? Usually checks whether the expression arguments are actual fields that exist in Lucene. See TranslationAware.Translatable for precisely what can be signaled from this method.

Specified by:

translatable in interface TranslationAware

Overrides:

translatable in class FullTextFunction

translate

protected Query translate(LucenePushdownPredicates pushdownPredicates,
 TranslatorHandler handler)

Specified by:

translate in class FullTextFunction

withFilters

public Expression withFilters(List<Expression> filterExpressions)

evaluatorQueryBuilder

protected QueryBuilder evaluatorQueryBuilder()

Description copied from class: FullTextFunction

Returns the query builder to be used when the function cannot be pushed down to Lucene, but uses a LuceneQueryEvaluator instead

Overrides:

evaluatorQueryBuilder in class FullTextFunction

Returns:

the query builder to be used in the LuceneQueryEvaluator

postOptimizationVerification

public void postOptimizationVerification(Failures failures)

Description copied from interface: PostOptimizationVerificationAware

Validates the implementing expression - discovered failures are reported to the given Failures class.

Example: the Bucket function, which produces buckets over a numerical or date field, based on a number of literal arguments needs to check if its arguments are all indeed literals. This is how this verification is performed:

     

      @Override
      public void postOptimizationVerification(Failures failures) {
          String operation = sourceText();

          failures.add(isFoldable(buckets, operation, SECOND))
              .add(from != null ? isFoldable(from, operation, THIRD) : null)
              .add(to != null ? isFoldable(to, operation, FOURTH) : null);
      }
     
     

Specified by:

postOptimizationVerification in interface PostOptimizationVerificationAware

Overrides:

postOptimizationVerification in class FullTextFunction

replaceChildren

public Expression replaceChildren(List<Expression> newChildren)

Specified by:

replaceChildren in class Node<Expression>

info

protected NodeInfo<? extends Expression> info()

Specified by:

info in class Node<Expression>

getWriteableName

public String getWriteableName()

Specified by:

getWriteableName in interface NamedWriteable

writeTo

public void writeTo(StreamOutput out)
             throws IOException

Specified by:

writeTo in interface Writeable

Throws:

IOException

getFieldDataTypes

protected Set<DataType> getFieldDataTypes()

Description copied from class: SingleFieldFullTextFunction

Returns the set of allowed data types for the field parameter. Each subclass defines which field types it supports.

Specified by:

getFieldDataTypes in class SingleFieldFullTextFunction

getQueryDataTypes

protected Set<DataType> getQueryDataTypes()

Description copied from class: SingleFieldFullTextFunction

Returns the set of allowed data types for the query parameter. Each subclass defines which query types it supports.

Specified by:

getQueryDataTypes in class SingleFieldFullTextFunction

getAllowedOptions

protected Map<String,DataType> getAllowedOptions()

Description copied from class: SingleFieldFullTextFunction

Returns the allowed options map for this function. Keys are option names, values are the expected data types.

Specified by:

getAllowedOptions in class SingleFieldFullTextFunction

equals

public boolean equals(Object o)

Overrides:

equals in class SingleFieldFullTextFunction

hashCode

public int hashCode()

Overrides:

hashCode in class SingleFieldFullTextFunction