ss="indexterm"></a>
       </span> <a href="#GUC-PARALLEL-LEADER-PARTICIPATION" class="id_link">#</a></dt><dd><p>
         Allows the leader process to execute the query plan under
         <code class="literal">Gather</code> and <code class="literal">Gather Merge</code> nodes
         instead of waiting for worker processes.  The default is
         <code class="literal">on</code>.  Setting this value to <code class="literal">off</code>
         reduces the likelihood that workers will become blocked becau