On Mon, May 2, 2011 at 7:43 PM, Craig Ringer
<craig(at)postnewspapers(dot)com(dot)au> wrote:
> I'm now strongly in favour of keeping an internal key that users never
> see, and having separate user-visible identifiers. The users can demand
> that those identifiers change format or generation method and it's an
It's far easier to change a unique constraint on the fly than a PK in
a busy production database.