30分帮助分析sql语句的时间复杂度

[vividlife]

有一个数据表table，它的属性个数是n，记录个数是m。

那么下面两条select语句的时间复杂度怎么分析?
1、select sum(num) from
(
select power(count(*),2) as num from table
group by a,b,c
)
2、select sum(num) from
(
select count(*) as num from table
group by a,b,c
having count(distinct D)=1
)