I try to execute this query in AWS Redshift.
with test_1 as (
select 1 as "a" union select 2 as "a"
),
test_2 as (
select 1 as "b" union select 3 as "b"
)
select * from test_1 as t1 left outer join test_2 as t2 on t1.a = t2.b;
I got the result below.
| a | b |
|---|---|
| 1 | 1 |
| 2 | NULL |
The left outer is working as a simple left join.