# by memqcache_expire.  on by default.
memqcache_auto_cache_invalidation = on
</pre>

<p>修改这个参数的值后，重启 pgpool。</p>

<h4 id="invalidation_try">尝试自动失效的效果</h4>
<p>确认你可以从缓存中获得 SELECT 语句的结果。</p>
<pre>test=&gt; SELECT * FROM table_cache_ok WHERE a = 1;
LOG:   <b>query result fetched from cache.</b> statement: SELECT * FROM table_cache_ok WHERE a = 1;
</pre>

<p>在这个表中执行 INSERT INTO 。</p>
<pre>test=&gt; INSERT INTO table_ca