Re: Sequences change in a rolled-back transactions

Alvaro Herrera wrote:
> Erwin Moller wrote:
>
>> I thought a transaction that is rolled back, rolls back *everything*
>> done in that transaction.
>> Appearantly sequences are not included.
>
> Yes.  This is actually a desirable property, because it allows sequences
> to work fine in concurrent scenarios (which are, after all, the whole
> point of sequences).
>
> If you actually need an incremental number with no gaps (which is rare
> but not unseen), you need to use some other mechanism, which will
> probably involve a lock to prevent concurrency.

If so, search the list archives for "gapless sequence". You'll see lots
of explanations of options and of the problems with them.

--
Craig Ringer