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Vector search

Last Updated: Sep 09, 2021


To meet more diversified and complex business requirements, OpenSearch provides the vector search feature. In specific business scenarios, especially test question search and image search scenarios, you can use the vector search feature together with the multi-path search feature to improve the accuracy of search results. This topic describes the syntax and usage notes of vector indexes.


query = Vector index:Vector

Example: Use a 64-dimensional vector index to query data
vector: '0.377796,-0.958450,0.409853,-0.238177,-1.293826,0.356797,-0.295727,0.847301,-1.220337,0.148032,-1.128458,0.903187,0.509352,0.293686,-1.005852,-0.488839,0.888227,-0.555556,-0.658025,0.267552,-0.567601,0.003045,0.591734,-0.515983,-1.316453,-1.462450,0.091946,1.554954,0.384802,0.720498,0.144338,1.217826,0.724039,0.044212,0.571332,-1.425430,0.618965,0.481887,-1.617787,1.505416,-0.683652,1.030900,0.562021,0.162437,0.816546,0.112229,-0.739288,-0.342643,-0.199292,0.508368,-1.384887,-1.842170,0.952622,-1.699499,0.199430,-0.232464,-0.273227,-0.383696,-0.511302,0.005458,1.873572,-0.926169,-0.417587,-0.660156'

Usage notes

  • Vector indexes are applicable only to fields of the DOUBLE_ARRAY type.

  • OpenSearch supports 64-dimensional, 128-dimensional, and 256-dimensional vector analyzers. Fields of the DOUBLE_ARRAY type must also contain 64, 128, or 256 elements to match each type of vector analyzer.

  • The maximum length of a vector index is 4 KB before encoding. A query supports up to two vector indexes.