rnal-link">print</a></span><span class="op">(</span><span class="fu">columns_used</span><span class="op">(</span><span class="va">optree</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span>  <span class="fu">DBI</span><span class="fu">::</span><span class="fu"><a href="https://dbi.r-dbi.org/reference/dbDisconnect.html" class="external-link">dbDisconnect</a></span><span class="op">(</span><span class="va">my_db</span><span class="op">)</span></span></span>
<span cl