Re: [PATCH] Return command tag 'REPLACE X' for CREATE OR REPLACE statements.

On mån, 2011-01-17 at 10:05 -0500, Robert Haas wrote:
> On Mon, Jan 17, 2011 at 9:41 AM, Peter Eisentraut <peter_e(at)gmx(dot)net> wrote:
> > On fre, 2011-01-14 at 18:45 -0500, Robert Haas wrote:
> >> On Fri, Jan 14, 2011 at 3:45 PM, Marti Raudsepp <marti(at)juffo(dot)org>
> >> wrote:
> >> > There's a similar case with CREATE TABLE IF NOT EXISTS, maybe this
> >> is
> >> > worth covering in an updated patch too?
> >> > And if I change that, people might expect the same from DROP X IF
> >> EXISTS too?
> >>
> >> It's far less clear what you'd change those cases to say, and they
> >> already emit a NOTICE, so it seems unnecessary.
> >
> > Maybe instead of the proposed patch, a notice could be added:
> >
> > NOTICE: existing object was replaced
>
> Well, that would eliminate the backward-compatibility hazard, pretty
> much, but it seems noisy. I already find some of these notices to be
> unduly informative.

I'm also anti-NOTICE.

I'm just saying, we propose that CREATE OR REPLACE should return a tag
of CREATE or REPLACE depending on what it did, then DROP IF NOT EXISTS
should also return a tag of DROP or ??? depending on what it did. Since
the latter question was settled by a notice, that would also be the
proper answer for the former.

Perhaps the next thing is that MERGE should return INSERT or UPDATE
depending on the outcome?