Re: UPSERT wiki page, and SQL MERGE syntax

On Wed, Oct 8, 2014 at 5:37 PM, Marti Raudsepp <marti@juffo.org> wrote:
> Only in case the trigger changes *key* columns necessary for atomicity
> (i.e. from the WITHIN index). Other columns are fair game. The
> restriction seems justifiable to me: it's unreasonable to be atomic
> with respect to values that change mid-way.

> If you don't see any reasons why it can't be done, these benefits seem
> clear to me. I think the tradeoffs at least warrant wider discussion.

I don't.  That's very surprising. One day, it will fail unexpectedly.
As proposed, the way BEFORE INSERT triggers fire almost forces users
to consider the issues up-front.

Note that the CONFLICTING() behavior with respect to BEFORE INSERT
triggers work's the same as MySQL's "INSERT ON DUPLICATE KEY UPDATE
foo = VALUES(foo)" thing. There was agreement that that was the right
behavior, it seemed.

-- 
Peter Geoghegan