les, or the
        storage file for a held cursor.  A transaction attempting to exceed
        this limit will be canceled.
        If this value is specified without units, it is taken as kilobytes.
        <code class="literal">-1</code> (the default) means no limit.
        Only superusers and users with the appropriate <code class="literal">SET</code>
        privilege can change this setting.
       </p><p>
        This setting constrains the total space used at any instant by all
        temporary fi