How to Hide WP-DBManager Admin Menus

function plt_hide_wp_dbmanager_menus() {
	//Hide "Database".
	remove_menu_page('wp-dbmanager/database-manager.php');
	//Hide "Database → Database".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-manager.php');
	//Hide "Database → Backup DB".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-backup.php');
	//Hide "Database → Manage Backup DB".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-manage.php');
	//Hide "Database → Optimize DB".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-optimize.php');
	//Hide "Database → Repair DB".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-repair.php');
	//Hide "Database → Empty/Drop Tables".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-empty.php');
	//Hide "Database → Run SQL Query".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/database-run.php');
	//Hide "Database → DB Options".
	remove_submenu_page('wp-dbmanager/database-manager.php', 'wp-dbmanager/wp-dbmanager.php');
}

add_action('admin_menu', 'plt_hide_wp_dbmanager_menus', 11);

Where do I put this code?