def start_rds_backup(db, s3_bucket, s3_backup_object_path, cursor):
    """
    Trigger dbo.rds_backup_database procedure and return its task id.
    """
    cursor.execute(
        """
        EXEC msdb.dbo.rds_backup_database
            @source_db_name={},
            @s3_arn_to_backup_to='arn:aws:s3:::{}/{}',
            @overwrite_S3_backup_file=1,
            @type='full';
    """
        .format(db, s3_bucket, s3_backup_object_path))
    return cursor.fetchall()[0][0]
