Ajax first call
<p>I have a script that process data with some ajax call, depending on the user clicks and changes the call is done once again(works fine).</p>

<pre><code>$.ajax({
   type: "POST",
   url: "process_data.php",
   data: { action: "first_action",data:data},
   dataType: 'json',
   success:function(result){
       //process
   },
   error: function(XMLHttpRequest, textStatus, errorThrown) {
   }
 });
</code></pre>

<p>To save time I want to execute some queries in my <code>process_data.php</code> file only during the first ajax call and save them into variables so I dont have to execute the same queries in every call.
How to catch ajax first call ?</p>