</request>  

      <for from="1" to="999999" var="counter">

        <for from="1" to="100" var="counter">
          <setdynvars sourcetype="random_number" start="1" end="999999999"> 

            <var name="rnd_uid" />
          </setdynvars>

         <setdynvars sourcetype="random_string" length="52">
           <var name="rnd_profile" />

         </setdynvars>

         <request subst="true">
            <mysql type="sql">update   user set profile = "%%_rnd_profile%%" where tid = %

%_rnd_uid%% </mysql>
         </request> 

        </for>
        <thinktime min="2" max="5" random="true" />

      </for>

      <request>
        <mysql type="close"></mysql>

      </request>
  </session>

 </sessions>

</tsung>