Re: string_to_array has to be stable?

On Thu, Jul 29, 2010 at 1:10 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Thu, Jul 29, 2010 at 1:00 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Or we could decide that volatile domain CHECK expressions are un-sensible
>>> and just relabel all these input functions as stable, which would make
>>> everything consistent.  Thoughts?
>
>> Aren't volatile CHECK expressions pretty un-sensible in general?
>
> Yeah, probably so.  I can't think of a use-case that seems like it would
> justify the possible performance hit from having to assume all functions
> performing datatype input calls are volatile.

That's my thought, too. Any non-immutable CHECK constraint is
basically playing with fire, to some degree. But a stable check
constraint is at least playing with it somewhat responsibly, whereas a
volatile check constraint strikes me as more like doing it while
bathing in turpentine.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company