Function

A Function instance defines a built-in function (e.g., BM25, text embedding) that can be attached to a collection schema.

go
type Function struct {
    Name string
    Description string
    Type FunctionType
    InputFieldNames []string
    OutputFieldNames []string
    Params map[string]string
}

FIELDS:

Name (string) -

The name of the function.
Description (string) -

The human-readable description of the function.
Type (FunctionType) -

The type of the function, such as BM25 or Rerank.
InputFieldNames ([]string) -

The names of the input fields the function reads.
OutputFieldNames ([]string) -

The names of the fields the function writes its output to.
Params (map[string]string) -

The function parameters as key-value pairs.

BUILDER METHODS:

WithName(name string)

Sets the name of the function.
WithInputFields(inputFields ...string)

Sets the input field names for the function.
WithOutputFields(outputFields ...string)

Sets the output field names for the function.
WithType(funcType FunctionType)

Sets the function type (BM25, MinHash, TextEmbedding, Rerank).
WithParam(key string, value any)

Sets a function parameter key-value pair.

METHODS:

Clone() *Function

Returns a deep copy of f.

Example

Demonstrates Function usage.

go
import (
    "github.com/milvus-io/milvus/client/v3/entity"
)

// Define a BM25 text embedding function on a VarChar field
fn := entity.NewFunction().
    WithName("bm25_fn").
    WithType(entity.FunctionTypeBM25).
    WithInputFields("text").
    WithOutputFields("sparse_vector")

schema := entity.NewSchema().
    WithName("my_collection").
    WithField(entity.NewField().WithName("id").WithDataType(entity.FieldTypeInt64).WithIsPrimaryKey(true)).
    WithField(entity.NewField().WithName("text").WithDataType(entity.FieldTypeVarChar).WithMaxLength(1000).WithEnableAnalyzer(true)).
    WithField(entity.NewField().WithName("sparse_vector").WithDataType(entity.FieldTypeSparseVector)).
    WithFunction(fn)

Example​

Example