Re: feature request ctid cast / sql exception

"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> On Sat, Apr 17, 2021 at 10:58 AM Vladimír Houba ml. <v(dot)houba(at)gmail(dot)com>
> wrote:
>> Another nice feature would be a function that can be called from a sql
>> statement and would throw an exception when executed.

> An assertion-related extension in core would be welcomed.

This has been suggested before, but as soon as you start looking
at the details you find that it's really hard to get a one-size-fits-all
definition that's any simpler than the existing plpgsql RAISE
functionality. Different people have different ideas about how
much decoration they want around the message. So, if 10% of the
world agrees with your choices and the other 90% keeps on using
a custom plpgsql function to do it their way, you haven't really
improved matters much. OTOH a 90% solution might be interesting to
incorporate in core, but nobody's demonstrated that one exists.

regards, tom lane