1.6.7.7.7.2.9.1.3" class="indexterm"></a>
       </span> <a href="#GUC-OLD-SNAPSHOT-THRESHOLD" class="id_link">#</a></dt><dd><p>
         Sets the minimum amount of time that a query snapshot can be used
         without risk of a <span class="quote">“<span class="quote">snapshot too old</span>”</span> error occurring
         when using the snapshot.  Data that has been dead for longer than
         this threshold is allowed to be vacuumed away.  This can help
         prevent bloat in the face of snap