title: ON DELETE SET DEFAULT - unimplemented feature
body: <p>While creating  table .</p>
  
  <p>A error messege is showing <code>SQL Error: ORA-03001: unimplemented feature</code> </p>
  
  <pre><code>CREATE TABLE OrgChart
    (
      job_title VARCHAR(30) NOT NULL PRIMARY KEY,
      emp_nbr   INTEGER DEFAULT 0 NOT NULL REFERENCES Personnel(emp_nbr) ON
    DELETE SET DEFAULT ON
    UPDATE CASCADE,
      boss_emp_nbr INTEGER REFERENCES Personnel(emp_nbr),
      UNIQUE (emp_nbr, boss_emp_nbr),
      salary DECIMAL (12,4) NOT NULL CHECK (salary &gt;= 0.00)
    );
  </code></pre>
  
  <p>How do I declare a foreign key that allows updates to cascade from the parent table and that sets the value to the default (0 in this case) when the parent row is deleted?</p>