Re: What happened to the is_<type> family of functions proposal?

On Wednesday 22 September 2010 01:05:39 Tom Lane wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > I don't understand the argument that we need type input functions to
> > be protected by a savepoint. That seems crazy to me. We're taking a
> > huge performance penalty here to protect against something that seems
> > insane to me in the first instance. Not to mention cutting ourselves
> > off from really important features, like the ability to recover from
> > errors during COPY. I don't understand why we can't just make some
> > rules about what type input functions are allowed to do.
>
> There are many rules that you could possibly make for type input
> functions. But "you cannot throw an error" is not one of them ---
> or at least, not one that you can usefully expect to be followed
> for anything more than trivial straightline code.
>
> The poster child for this is of course domain_in(). But even without
> that, I don't think you can realistically legislate that no errors be
> thrown by something of the complexity of, say, the timestamp input
> functions. Just for starters, what of a palloc() failure?
Uhm. Isnt a palloc failure a really, really bad example because it will kill
the session anyway? FATAL+ is not relevant in that context, right?

Andres