今天在刷新公司項目頁面時發現有個板塊一直刷新不出數據，最后發現接口報錯（504 Gateway Time-out)
通過查看代碼發現有個sql語句，如下，特別慢
select `vdc1`,
`vdc2`,
`vdc3`,
`vdc4`,
`vdc5`,
`vdc6`,
`vdc7`,
`vdc8`,
`idc1`,
`idc2`,
`idc3`,
`idc4`,
`idc5`,
`idc6`,
`idc7`,
`idc8`,
`pdc1`,
`pdc2`,
`pdc3`,
`pdc4`,
`pdc5`,
`pdc6`,
`pdc7`,
`pdc8`,
`record_time`
from `t_inverter_dc_side_data`
where `inverter_code`= '7d006910-cce1-11e6-8c15-67da3e10436c'
and `record_time` like '2018-01-17%'
order by `record_time` desc
limit 1
用explain分析如下