code: def upgrade(url):
      """
      Upgrade the schema of an MLflow tracking database to the latest supported version.
  
      **IMPORTANT**: Schema migrations can be slow and are not guaranteed to be transactional -
      **always take a backup of your database before running migrations**. The migrations README,
      which is located at
      https://github.com/mlflow/mlflow/blob/master/mlflow/store/db_migrations/README.md, describes
      large migrations and includes information about how to estimate their performance and
      recover from failures.
      """
      import mlflow.store.db.utils
  
      engine = (
          mlflow.store.db.utils.create_sqlalchemy_engine_with_retry(url)
      )
      mlflow.store.db.utils._upgrade_db(engine)
  
label_desc: Use image node_id 2 for calling a global function with example usage: upgrade(url) without return types