"Robert Fritzsching" <robert(dot)fritzsching(at)gmx(dot)net> writes:
> If I insert data in a table with left outer join, I get no error even though
> the domain type should trigger an error.
This has been discussed before. Most of us think it's a bug in the SQL
spec that the issue even exists. What would you expect to happen with
an outer join that has a not-null-domain output column?
regards, tom lane