code: def define_database_config(config):
      """Create and define the fields of the database configuration."""
      database_config = Configuration()
  
      database_config.add_option(
          "name",
          option_type=str,
          default="orion",
          env_var="ORION_DB_NAME",
          help="Name of the database.",
      )
      database_config.add_option(
          "type",
          option_type=str,
          default="PickledDB",
          env_var="ORION_DB_TYPE",
          help=(
              "Type of database. Builtin backends are ``mongodb``, "
              "``pickleddb`` and ``ephemeraldb``."
          ),
      )
      database_config.add_option(
          "host",
          option_type=str,
          default="",
          env_var="ORION_DB_ADDRESS",
          help="URI for ``mongodb``, or file path for ``pickleddb``.",
      )
      database_config.add_option(
          "port",
          option_type=int,
          default=27017,
          env_var="ORION_DB_PORT",
          help="Port address for ``mongodb``.",
      )
  
      config.database = database_config
  
file_path: orion/src/orion/core/__init__.py
imports: import logging
  import os
  import socket
  from appdirs import AppDirs
  from orion.core.io.config import Configuration
  from ._version import get_versions
label_desc: Use image node_id 4 for calling a global function with example usage: define_database_config(config) without return types