By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
select * from (select '123' as col1 from dual
union all
select '456' from dual) a, (select 'abc' as col2 from dual) b
| COL1 | COL2 |
|---|---|
| 123 | abc |
| 456 | abc |
| COL1 | COL2 |
|---|---|
| 123 | abc |
| 456 | abc |