ce is used to map these files into your application's
           address space. If <code class="literal">mmap</code> 
           is not available, then the UNIX <code class="literal">shmget</code> interfaces 
           are used instead (again, if they are available).
        </p>
            <p>
            In this default case, the region files are named
            <code class="literal">__db.###</code>
            (for example, <code class="literal">__db.001</code>, <code class="literal">__db.002</code>,