SELECT from_unixtime(timestamp,'%Y-%m-%d') day, count(distinct(mac)) macsum FROM `list` WHERE (`timestamp` BETWEEN 1494604800 AND 1495166463) AND (`softId`=1) GROUP BY `day` ORDER BY `day` DESC建了索引 timestamp,mac,excType,softid 目前300多万条的数据查询耗时要3到4秒,请问有什么优化的空间吗?
from
(
SELECT from_unixtime(timestamp,'%Y-%m-%d') day,
mac
FROM `list`
WHERE (`timestamp` BETWEEN 1494604800 AND 1495166463) AND (`softId`=1)
GROUP BY `day`
) v
group by day
ORDER BY `day` DESC