在不杀死与mySQL服务器的PHP连接的情况下进行多次ajax调用？

I'll be making multiple ajax calls (maybe 5 in a second and then 0 for 10-100 seconds and then maybe 10 in a second or something like that) in brief intervals.

Is there any way I can avoid starting a new mySQL db connection each time so I don't kill my server?

I'll be using jQuery to make a $.post call 5 times to a php page that might look like this:

<?php

db_connection_method();

$variable = $_POST['data'];

mysql_query();

?>