Re: UPSERT wiki page, and SQL MERGE syntax

On Thu, Oct 9, 2014 at 1:51 AM, Peter Geoghegan <pg(at)heroku(dot)com> wrote:
> On Wed, Oct 8, 2014 at 2:01 PM, Kevin Grittner <kgrittn(at)ymail(dot)com> wrote:
>> Although the last go-around does suggest that there is at least one
>> point of difference on the semantics. You seem to want to fire the
>> BEFORE INSERT triggers before determining whether this will be an
>> INSERT or an UPDATE. That seems like a bad idea to me

Indeed, the current behavior breaks even the canonical "keep track of
how many posts are in a thread" trigger example because INSERT
triggers are fired for an effective row UPDATE. I can't see how that's
acceptable.

> Well, it isn't that I'm doing it because I think that it is a great
> idea, with everything to recommend it. It's more like I don't see any
> practical alternative.

I proposed an alternative that avoids this surprise and might allow
some other benefits. Can you please look into that? Even a "clarify
this", "this couldn't possibly work" or "you're not a major
contributor so your arguments are invalid" response. ;)

I admit I initially misunderstood some details about the current
behavior. I can dig into the code and write a clearer and/or more
detailed spec if I had even *some* feedback.

Regards,
Marti