 parameter. When the filename is <code class="literal">NULL</code>, the database is not
        backed by the filesystem.
    </p>
      <pre class="programlisting">    /*
     * If we had utility threads (for running checkpoints or 
     * deadlock detection, for example) we would spawn those
     * here. However, for a simple example such as this,
     * that is not required.
     */

    /* Open the database */
    ret = open_db(&amp;dbp, prog_name, <strong class="userinput"><code>NULL</code></strong>, 
