On ons, 2010-06-30 at 10:38 -0400, Tom Lane wrote:
> Magnus Hagander <magnus@hagander.net> writes:
> > Shouldn't we disallow anything that's not IMMUTABLE in a check constraint?
>
> I think you'd get too many howls of pain ... also, such a restriction is
> likely contrary to SQL spec.
<kibo>
"The <search condition> shall simply contain a <boolean value
expression> that is retrospectively deterministic."
This is then defined in a rather complex manner that ends up disallowing
col > now() but allowing col < now().
</kibo>
