@Override
  public boolean isConstraintSupportedAfterNullability() {
    return false;
  }
{@inheritDoc}
<p/>
Oracle supports the format:

<pre>
ALTER TABLE foo ADD COLUMN bar varchar2(32) DEFAULT 'baz' NOT NULL
</pre>

This syntax doesn't allow contraints added after the {@code NULL}
constraint.
ambari-server/src/main/java/org/apache/ambari/server/orm/helpers/dbms/OracleHelper.java