Re: sequence advances on failed insert

David Fetter presumably uttered the following on 04/07/05 20:16:
> On Thu, Apr 07, 2005 at 07:59:52PM -0400, Matthew Terenzio wrote:
>
>>I'm noticing that a sequence is advancing even if the insertion
>>fails.  Is this weird or expected?
>
>
> It's expected.  Sequences are guaranteed to generate unique IDs.
> These happen to be an increasing sequence of integers, but there is no
> attempt to make this a gap-free sequence, and your apps should not
> depend on the actual value of said ID.

I assume by "not depend on the actual value" that one should not assume
that the next value will be one increment higher than the current
highest value in the table; because it is guaranteed to be unique, I
would think it to be an excellent way to assign a customer id, for
example, which can then be referenced (foreign key, etc) by other tables
after a new record is added. Unless there is some other reason one
should not use a sequence value as any type of identifier?

Sven