Re: Sequence bug or feature?

"rob" <rob(at)cabrion(dot)com> writes:
> It appears that sequence.last_value and nextval('sequence') are out of sync
> when first created. My comments below are in [brackets]. Is this by design
> or is this a bug? Does this conform to SQL92? TIA.

It's by design. Note the is_called flag, which might be better named
ever_advanced or some such. The initial state is last_value = initial
value, is_called = false. The first nextval changes is_called to true;
subsequent ones increment last_value. So last_value is the last value
assigned only if a value has ever been assigned, ie, is_called is true.

This is a little bit baroque, agreed. I think the idea was to allow
sequences to start at MININT without creating arithmetic-overflow
issues.

regards, tom lane