您可以使用以下方法：

with t1 as (
  select 'A1' col1,'V1' col2 union all
  select 'A1' col1,'V1' col2 union all
  select 'A2' col1,'V2' col2 union all
  select 'A3' col1,'V3' col2 union all
  select 'A3' col1,'V3' col2 union all
  select 'A3' col1,'V3' col2 union all
  select 'A4' col1,'V4' col2
),
t2 as (
  select 'A1' col1,'V1' col2 union all
  select 'A2' col1,'V2' col2 union all
  select 'A3' col1,'V3' col2
),
t1_with_rn as (
  select t1.*, row_number() over(partition by t1.col1, t1.col2) rn from t1
)
select 
  t1_with_rn.col1, t1_with_rn.col2
from 
  t1_with_rn
  left join t2 on (t1_with_rn.col1 = t2.col1 and t1_with_rn.col2 = t2.col2 and t1_with_rn.rn = 1)
where
  t2.col1 is null and t2.col2 is null