Re: psql \d option list overloaded

Tom Lane wrote:
> But this interacts with point 3 (psql breaks on every new backend
> version). It's not desirable to have every GUI and large custom
> program implementing its own set of metadata inquiry commands: they
> all have to go through the same update pain as psql. Perhaps if
> people start to rely on information_schema for those things, life
> will get better, but I'm unconvinced that will happen. psql itself
> certainly hasn't moved in that direction.

IIRC, the two killers in psql compatibility have been outer joins and
schemas. I don't see how we could have avoided that, except with
highly specialized and static (parameter-less) commands. There have
been additional minor issues, but I suppose we could have avoided those
if we had cared to do so at all.

Several people have in the past proposed to keep psql backward
compatible, even if only by means of

if (version =x) {
...
}
else if (version = y) {
...
}

(which would be fine by me), but apparently no one has felt pressed
enough yet.