Updating external tables in Oracle

The trick we will use to make DML possible consists of three steps:

1. Define a view on the external table.
    
2. On this view, define INSTEAD OF triggers for insert, update and delete.
    
3. Write PL/SQL code in these triggers to perform the required processing.

Kok then shows examples of the code and offers a free download of his technique, and offers important caveats:

The problem is with doing a multiple delete (i.e. a delete statement that affects more than one row). As we noted before, the INSTEAD OF trigger is implicitly for each row. This means statement-level information is unavailable.

create or replace view emp_ext_tab_vw
as
  select       rownum         rownumber
         , emp.empno          empno
         , emp.ename          ename
         , emp.job            job
         , emp.mgr            mgr
         , emp.hiredate       hiredate
         , emp.sal            sal
         , emp.comm           comm
         , emp.deptno         deptno
  from     emp_ext_tab        emp
  order by rownumber asc
/
 

create or replace trigger emp_ext_tab_vw_brd
instead of delete on emp_ext_tab_vw
begin
  --
  emp_ext_tab_dml.delete_record ( :OLD.rownumber );
  --
end;
/