David Fetter <david@fetter.org> writes:
> On Thu, Jan 29, 2009 at 08:12:12PM -0500, Tom Lane wrote:
>> "David E. Wheeler" <david@kineticode.com> writes:
>>> Seems to me that IS DISTINCT FROM is just another operator, like =,
>>
>> Wishful thinking...
> What would it take to make this wish come true?
I don't think we want it to come true. If we treat IS DISTINCT FROM
as a weirdly-named operator then we have to provide an implementation
for every datatype (oh, and another one for IS NOT DISTINCT FROM).
The PITA factor is enormous. Much better to handle it the way we
are now, where it's a specialized expression node type.
To get it to work with ANY/ALL you'd probably need some special hack to
create new sublink types, or something like that. Also a PITA, but
a lot more localized ...
regards, tom lane
