add_collection_field()

This operation adds a new scalar field to an existing collection without recreating it. The field becomes available almost immediately with minimal delay due to internal schema synchronization.

Request Syntax

add_collection_field(
    collection_name: str,
    field_name: str,
    data_type: DataType,
    desc: str = "",
    timeout: Optional[float] = None,
    **kwargs
)

PARAMETERS:

• collection_name (string) –

  [REQUIRED]

  The name of the target collection.

• field_name (string) –

  [REQUIRED]

  The name of the new field.

• data_type (DataType) –

  [REQUIRED]

  The data type of the new field. See DataType for supported types.

• desc (string, optional) –

  A brief description of the field.

• timeout (float) –

  Timeout (in seconds) for the RPC request. If None, the call waits indefinitely.

• kwargs (dict, optional) –

  Additional parameters include:

  • nullable (bool):

    Must be set to True for dynamically added fields to accommodate existing entities that don’t have values for the new field.

  • default_value (DataType-specific):

    A default value for the field if none is provided during data insertion.

  • max_length (int):

    Required for DataType.VARCHAR fields. Sets the maximum allowed byte length for strings (1 to 65,535).

  • element_type (DataType):

    Required for DataType.ARRAY fields. Specifies the data type of elements within the array.

  • max_capacity (int):

    Required for DataType.ARRAY fields. Defines the maximum number of elements in the array.

RETURN TYPE:

None

EXCEPTIONS:

• MilvusException

  This exception will be raised when any error occurs during this operation.

Examples

Example 1: Add a basic nullable field

client.add_collection_field(
    collection_name="product_catalog",
    field_name="created_timestamp",
    data_type=DataType.INT64,
    nullable=True  # Required for added fields
)

Example 2: Add a field with default value

client.add_collection_field(
    collection_name="product_catalog",
    field_name="priority_level",
    data_type=DataType.VARCHAR,
    max_length=20,
    nullable=True,          # Required for added fields
    default_value="standard"  # Default value for existing entities
)