Re: [HACKERS] Updating column on row update

On Tue, Nov 24, 2009 at 2:07 PM, Kevin Grittner
<Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
>> If it did so, that would be outside the apparent meaning of the
>> command, which is to do nothing if an object of that name exists.
>> That's why we've gone with CREATE OR REPLACE instead.
>
> I think that "fail on existence of an object conflicting with given
> definition" is behavior which could be documented and rates fairly
> low on my astonishment scale.  (I can't speak for anyone else.)

I think CINE should create the object if it does not exist and
otherwise do nothing. It might be useful to have some kind of
consistency-checking behavior, but it would probably be more useful if
decoupled from CINE, and in any case, that's not what "CREATE IF NOT
EXISTS" means to me.

> I am skeptical that, in the absence of built-in support for checking
> the existing object against the supplied definition, people would
> generally go any further than Andrew's example.  When they did, I'm
> skeptical about how often they would get the details exactly right.

Bingo.

...Robert