Greg Stark <gsstark@mit.edu> writes:
> I wonder if we could get around this by inventing a new type
> date_or_interval which looks at the input and decides which it is
> using fairly strict rules. date_sub would take that type and do the
> appropriate operation based on what the constant had in it.
Ick. This would be a pretty enormous blot on the type system to solve
one special case, in a manner that would only be helpful to newbies
who don't know that they ought to cast to eliminate the ambiguity.
In fact it sounds quite a bit like the implicit-cast-to-text situations
we just finished getting rid of ...
regards, tom lane