          Support retrieval from the Btree using record numbers.     
            </p>
            <p>
                 Logical record numbers in Btree databases are mutable in the face of
                 record insertion or deletion. See the <span class="bold"><strong>-renumber</strong></span> argument for further discussion.
            </p>
            <p>
                 Maintaining record counts within a Btree introduces a serious point of
                 contention, namely the page locations where 