sql需求記錄一二

需求：
求當前業務種類在十二個月份中每個月的佔比。
數據表：p016_counter_biz_stat
方法一：
select
‘在業務總量中的佔比’ as legend，
round(t.trans_num/(
select
sum(trans_num) as trans_num_sum
from
p016_counter_biz_stat t1
where org_id = #{}
and agent_id=#{}
and t1.summ_date=t.summ_data) *100,2),
to_char(t.summ_date,‘yyyy-mm’) as xAxis,
2 as value2
from
p016_counter_biz_stat t
where org_id = #{}
and agent_id=#{}
and t.biz_type =#{}
and to_char( summ_date,‘yyyy-mm’)
between (select to_char(date(max(summ_date)-interval ‘11 month’),‘yyyy-mm’) from p016_counter_biz_stat)
and (select to_char(date(max(summ_date)),‘yyyy-mm’) from p016_counter_biz_stat)
order by t.summ_date

方法二：
select
‘在業務總量中的佔比’ as legend，
round(t1.trans_num/t2.trans_num_sum*100,2) as series,
t1.xAxis,
2 as value2
from(
( select
t.trans_num,
to_char(t.summ_date,‘yyyy-mm’) as xAxis,
from
p016_counter_biz_stat t
where org_id = #{}
and agent_id=#{}
and t.biz_type =#{}
and to_char( summ_date,‘yyyy-mm’)
between (select to_char(date(max(summ_date)-interval ‘11 month’),‘yyyy-mm’) from p016_counter_biz_stat)
and (select to_char(date(max(summ_date)),‘yyyy-mm’) from p016_counter_biz_stat)
order by t.summ_date ) t1
inner join(
select
sum(trans_num) as trans_num_sum,
to_char( summ_date,‘yyyy-mm’) as xAxis
from p016_counter_biz_stat
where org_id = #{}
and agent_id=#{}
and to_char( summ_date,‘yyyy-mm’)
between (select to_char(date(max(summ_date)-interval ‘11 month’),‘yyyy-mm’) from p016_counter_biz_stat)
and (select to_char(date(max(summ_date)),‘yyyy-mm’) from p016_counter_biz_stat)
group by summ_date
order by summ_date
) t2
on t1.xAxis=t2.xAxis
)
苦於沒有數據量，想問下各位數據大佬這倆sql，正常來說一樣數據量的前提下，哪個sql的執行效率更高，效率低的那個爲什麼低，主要是哪方面的原因。