Is polling in jQuery expensive, and are there alternatives?
<p>I have several users accessing my page at the same time, with each client polling (using 
setInverval) another php script that reads a value from a database and prints it.</p>

<pre><code>setInterval( "printData();", 300 );
</code></pre>

<p>I'm relatively new to jQuery and javascript, and I'm a bit skeptical of the viability of constantly running this php script and constantly making database queries.</p>

<p>Can someone calm my nerves or provide an alternative to my current method?</p>
