Re: Is a SERIAL column a "black box", or not?

On Mon, May 01, 2006 at 07:47:06PM -0400, Tom Lane wrote:
> "Jim C. Nasby" <jnasby(at)pervasive(dot)com> writes:
> > I think a big point that's being missed here is that SERIAL *is* trying
> > to be simple. If you need something more sophisticated or complex you
> > shouldn't be using SERIAL at all, you should be doing the stuff
> > yourself, by hand.
>
> I agree with this point in the abstract, but one important proviso is
> that it has to be *possible* to do it by hand. One good thing about
> the "SERIAL is just a macro" approach is that it keeps us honest about
> making sure that SERIAL isn't exploiting any weird internal behaviors
> that are hard to duplicate for handmade sequence defaults. We've
> already broken that to some extent by having the hidden dependency,
> and that in turn means that fairly-reasonable expectations like
> "pg_get_serial_sequence should find the column's associated sequence"
> don't work on handmade sequences. I don't want to go much further in
> that direction. If there's a usability problem we're trying to solve
> for SERIALs, we should make sure the problem gets solved for handmade
> sequences too.
>
> regards, tom lane

I agree with Tom's proviso and add one of my own, mentioned earlier.
It should be easy to use a sequence w/alter sequence almost all of
the time. The majority of the crowd should be able to use SERIAL in
the majority of cases. One reason I am adamant about this is the
v. useful dependencies that are (should be) set between the table
and the sequence when it is declared as a SERIAL.

--elein

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