>>>>From the response of people here, I believe my fear is irrational. The fear comes from knowing that there is no way to generate any unused values should the counter somehow skip ahead. I don't know how it would skip ahead; perhaps bug in my program(?).
>>>
>>>You can try to insert a record in a transaction, then rollback. My guess is that the counter would revert together with the transaction.
>>
>>Each time the counter changes and the value can be read in some way, will NEVER return back.
>
>That's why I said "within a transaction" - the new value should be invisible to all until the transaction closes.

I said "read in some way", as can be seen within a transaction, is a way, and a value is consumed.