php - Can someone please explain this mysql statement to me -

i trying learn mysql on own debugging php program. stuck. not understand particular statement or does:

$statusrequirements = array(     array(80*1024*1024*1024, 0.50, 0.40),     array(60*1024*1024*1024, 0.50, 0.30),     array(50*1024*1024*1024, 0.50, 0.20),     array(40*1024*1024*1024, 0.40, 0.10),     array(30*1024*1024*1024, 0.30, 0.05),     array(20*1024*1024*1024, 0.20, 0.0),     array(10*1024*1024*1024, 0.15, 0.0),     array(5*1024*1024*1024,  0.10, 0.0) ); $db->query("update users_main set requiredstatus=0.50 access>100*1024*1024*1024"); 

in simple english understand this:

database query update users_main , set required status 0.50 access greater 100 * 1024 * 1024 * 1024.

what don't understand significance of numbers 100*1024*1024*1024.

could please explain me?

if doing code inspection , reading code, 1 way be:

"in table users_main, update requiredstatus field 0.50 rows have access field greater 10g."