Order already created in checkout_confirmation

[wine9]

when I process to checkout_confirmation.php, I found there is a new order already created in mySQL, with order ID and all details. and at this moment, i checked in my previous order, that order is there too, where the customer still does not confirm the order yet.

 

I do not know if it is right or it is a bug. because I suppose an order should be created only when the customer click confirm button and go to payment process. before that, if the customer changes mind, the order should not be in database, but stay in shopping cart.

 

and also, i am looking into PHP code, I can not find where the order is actually insert into database, not in checkout_confirmation.php, not in order_total.php and order.php. So where the order is actually inserted into database?

 

anybody can help with that? thanks