uires the ability to determine whether a
         file exists and whether it is a file of type directory.
    </p>
      <p>
         The <code class="function">db_env_set_func_exists()</code> function configures all operations performed
         by a process and all of its threads of control, not operations
         confined to a single database environment.
    </p>
      <p>
         Although the <code class="function">db_env_set_func_exists()</code> function may be called at any time
         during the