sql-createtable.html#SQL-CREATETABLE-EXCLUDE">CREATE TABLE
   ... CONSTRAINT ... EXCLUDE</a>). Exclusion constraints allow the
   specification of constraints such as <span class="quote">“<span class="quote">non-overlapping</span>”</span> on a
   range type. For example:

</p><pre class="programlisting">
CREATE TABLE reservation (
    during tsrange,
    EXCLUDE USING GIST (during WITH &amp;&amp;)
);
</pre><p>

   That constraint will prevent any overlapping values from existing
   in the table at the s