Re: retroactive pg10 relnotes: sequence changes

On Tue, Aug 28, 2018 at 6:34 PM, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
wrote:

> Hello
>
> A customer of ours was taken by surprise by a change in Postgres 10 on a
> trial upgrade from 9.6. They were using sequences from SERIAL columns a
> little unorthodoxly, and their stuff stopped working: essentially, they
> hacked the default expression so that it'd automatically use negative
> numbers when the sequence reached INT_MAX. Since pg10 changed sequences
> to stop emitting values at that point, it raised an error rather than
> emit the negative numbers.
>
> (In 9.6 and prior, the sequence would emit values past INT_MAX; it was
> the column that raised the error. In pg10 things were changed so that
> it is now the sequence that raises the error.)
>
> My proposal now is to document this issue in the Postgres 10 release
> notes. "It's a little late for that!" I hear you say, but keep this in
> mind: many users have *not* yet upgraded to 10, and they'll keep doing
> it for years to come still. So I disagree that now is too late. We
> failed to warn people that already upgraded, but we're still on time to
> alert people yet to upgrade.
>
> I attach both the patch and a screenshot to show how minor the visual
> effect of the change is.
>
> (If people hate this, another option is to make it a separate bullet
> point.)
>

Looks reasonable to me. And I definitely think we should do it -- people
will be upgrading to 10 for years to come, so claiming it's too late is
definitely not correct.

--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>