No, it's not filling the holes (if you could think of a way to do that, that'd be awesome), but it is preventing a good portion of them. Like I said, the next autoindex is 23, my code will give 11. So it's like autoincrement, but smarter. It will use the numbers twice if the number no longer exists (only at the end of the number set).

But no. Unfortunatly, it wont fill holes.