title: Controlling the cache of a DataGrid
body: <p>I have implemented a virtual-scrolling DataGrid with an underlying QueryReadStore as follows</p>
  
  <pre><code>&lt;span dojoType="dojox.data.QueryReadStore" 
        jsId="logsStore" url="./logs.do" requestMethod="post"&gt;&lt;/span&gt;
  &lt;div  class="logsListContainer" 
        style="align: center; width: 100%; height: 100%; border: 0px"&gt;
      &lt;table height="100%" id="logs" jsId="logs" class="soria"
             dojoType="dojox.grid.DataGrid" store="logsStore" 
             rowsPerPage="20" keepRows="20" autoHeight="20"
             query="{action: 'logsList'}" autoRender="false"&gt;
  </code></pre>
  
  <p>I can see on the server's log that the rows are fetched by bunches of 20, which is a good thing, but it seems that they are kept in cache on the client side because they are never reread.
  This can be a problem when the number of rows is large.
  Is there a way to control how many rows are kept in cache? I thought that setting keepRows would do the trick, but obviously it does'nt.</p>