Обсуждение: Add IS (NOT) DISTINCT to subquery_Op

Is there any reason we couldn't/shouldn't support IS DISTINCT in 
subquery_Op? (Or really, just add support to ANY()/ALL()/(SELECT ...)?)
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com

Jim Nasby <Jim.Nasby@BlueTreble.com> writes:
> Is there any reason we couldn't/shouldn't support IS DISTINCT in 
> subquery_Op? (Or really, just add support to ANY()/ALL()/(SELECT ...)?)

It's not an operator (in the sense of something with a pg_operator OID),
which means this would be quite a bit less than trivial as far as internal
representation/implementation goes.  I'm not sure if there would be
grammar issues, either.
        regards, tom lane

On 12/10/15 7:03 PM, Tom Lane wrote:
> Jim Nasby <Jim.Nasby@BlueTreble.com> writes:
>> Is there any reason we couldn't/shouldn't support IS DISTINCT in
>> subquery_Op? (Or really, just add support to ANY()/ALL()/(SELECT ...)?)
>
> It's not an operator (in the sense of something with a pg_operator OID),
> which means this would be quite a bit less than trivial as far as internal
> representation/implementation goes.  I'm not sure if there would be
> grammar issues, either.

make_distinct_op() simply calls make_op() and then changes the tag of 
the result node to T_DistinctExpr. So I was hoping something similar 
could be done for ANY/ALL?
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com