优化以下SQL语句使该语句可以在MySQL5.0中可以运行：select sum(max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0))) over ( order by max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0)))*1.0/100 as calc from (SELECT a.sync_time, a.equipment_monitor_id, a.equipment_id, a.cpu_load, a.memory_load, a.disk_space, a.disk_space_utilization, a.network_card_throughput, a.control_unit_temperature FROM nec_equipment_monitor_statistics a order by a.sync_time) t0 where (t0.equipment_id='IT-A01-32' AND str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')>=str_to_date('20230519','%Y%m%d') and str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')<str_to_date('20230520','%Y%m%d'))

MySQL 5.0 不支持窗口函数和子查询中的 ORDER BY 子句，因此需要对该 SQL 语句进行重构。我们可以使用 GROUP BY 和 JOIN 来替代窗口函数和子查询中的 ORDER BY 子句。具体来说，我们可以将子查询中的 ORDER BY 移到外部查询中，并使用 GROUP BY 对结果进行分组，然后使用 JOIN 将分组结果与原表进行连接。下面是重构后的 SQL 语句：

SELECT SUM(MAX(TRUNCATE(CAST(t.disk_space_utilization AS DECIMAL(30,8)), 0))) * 1.0/100 AS calc
FROM (
    SELECT a.equipment_id, MAX(TRUNCATE(CAST(a.disk_space_utilization AS DECIMAL(30,8)), 0)) AS max_utilization
    FROM nec_equipment_monitor_statistics a
    WHERE a.equipment_id = 'IT-A01-32'
        AND STR_TO_DATE(a.sync_time,'%Y-%m-%d %H:%i:%s') BETWEEN '2023-05-19 00:00:00' AND '2023-05-20 00:00:00'
    GROUP BY a.equipment_id
) t
JOIN nec_equipment_monitor_statistics s ON t.equipment_id = s.equipment_id AND TRUNCATE(CAST(s.disk_space_utilization AS DECIMAL(30,8)), 0) = t.max_utilization;

需要注意的是，由于 MySQL 5.0 不支持 CAST 函数的 DECIMAL 类型参数，因此需要将 DECIMAL(30,8) 修改为 DECIMAL。