Max value for total hits in bigpipe virtual show o/p

Hi,

 

 

Can some one tell me, what the maximum possible value for total in output of bigpipe virtual show e.g.

 

(cur, max, limit, tot) = (978, 9187, 0, 18842083595) is

 

 

and what happens when it reaches the max?

 

 

Thanks,

 

Raja