<pre><code>c2.execute("delete from entity_map where canon_id in (select canon_id from
entity_map_session where canon_id in (select canon_id from
entity_map_session group by canon_id having count(canon_id) < 10))")
</code></pre>
<p>我想加快上述操作的速度。特别是我们删除行的最后一个。最好的方法是什么</p>