searchNearestVectors

open override fun searchNearestVectors(fieldName: String, target: FloatArray, knnCollector: KnnCollector, acceptDocs: Bits?)
open override fun searchNearestVectors(fieldName: String, target: ByteArray, knnCollector: KnnCollector, acceptDocs: Bits?)

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 a ScoreDoc for each nearest neighbor, in order of their similarity to the query vector (decreasing scores). The TotalHits contains the number of documents visited during the search. If the search stopped early because it hit visitedLimit, it is indicated through the relation TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO.

The behavior is undefined if the given field doesn't have KNN vectors enabled on its [ ]. The return value is never null.

Parameters

field

the vector field to search

target

the vector-valued query

knnCollector

collector with settings for gathering the vector results.

acceptDocs

Bits that represents the allowed documents to match, or null if they are all allowed to match.