title: How to understand the storage of data in cep？
body: <pre><code>Pattern&lt;Event, ?&gt; pattern = Pattern.&lt;Event&gt;begin(&quot;start&quot;)
      .next(&quot;middle&quot;).where(new SimpleCondition&lt;Event&gt;() {
          @Override
          public boolean filter(Event value) throws Exception {
              return value.getName().equals(&quot;error&quot;);
          }
      }).followedBy(&quot;end&quot;).where(new SimpleCondition&lt;Event&gt;() {
          @Override
          public boolean filter(Event value) throws Exception {
              return value.getName().equals(&quot;critical&quot;);
          }
      }).within(Time.seconds(10));
  </code></pre>
  <p>In this example within(Time.seconds(10)),</p>
  <p>1、Does it mean that the data is valid for 10 seconds ?</p>
  <p>2、Is the expiration data will be deleted after 10s ？</p>
  <p>3、if i dont set within(Time.seconds(10)), is data always valid？data dont be detele？</p>
  <p>4、if i dont set within(Time.seconds(10))，with more and more data, is it oom ? how to save the data?</p>
  <p>thank your help ^^</p>