Re: Error on failed COMMIT

Dave Cramer <davecramer(at)postgres(dot)rocks> writes:
> On Fri, 14 Feb 2020 at 14:37, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> I'm not trying to deny that you might find some other server behavior
>> more convenient. You might. And, to Vik's original point, it might be
>> more compliant with the spec, too. But since changing that would have
>> a pretty big blast radius at this stage, I think it's worth trying to
>> make things work as well as they can with the server behavior that we
>> already have. And I don't really see anything preventing the driver
>> from doing that technically. I don't understand the idea that the
>> driver is somehow not allowed to notice the command tag.

> We have the same blast radius.
> I have offered to make the behaviour requested dependent on a configuration
> parameter but apparently this is not sufficient.

Nope, that is absolutely not happening. We learned very painfully, back
around 7.3 when we tried to put in autocommit on/off, that if server
behaviors like this are configurable then most client code has to be
prepared to work with every possible setting. The argument that "you can
just set it to work the way you expect" is a dangerous falsehood. I see
no reason to think that a change like this wouldn't suffer the same sort
of embarrassing and expensive failure that autocommit did.

regards, tom lane