with Oracle9i, the confusing outer join
syntax using the ?(+)? notation has been
superseded by ISO 99 outer join syntax.
As we know, there are three types of outer
joins, left, right, and full outer join.
The purpose of an outer join is to include
non-matching rows, and the outer join
returns these missing columns as NULL
the syntax differences between these
variations in join syntax:
e.department_id = d.department_id(+);
join: Oracle9i and beyond
e.department_id = d.department_id;