Re: Proposal: revert behavior of IS NULL on row types - Mailing list pgsql-hackers

>>>>> "David" == David G Johnston <david.g.johnston@gmail.com> writes:
>> 2. x IS NOT NULL  if and only if  NOT (x IS NULL)
David> ​I would rather prohibit "IS NOT NULL" altogether.​ If one needsDavid> to test "NOT (x IS NULL)" they can write
itthat way. 

Prohibiting IS NOT NULL is not on the cards; it's very widely used.
>> Whole-row vars when constructed never contain the null value.
David> ...but what does this mean in end-user terms?​

It means for example that this query:
 select y from x left join y on (x.id=y.id) where y is null;

would always return 0 rows.

--
Andrew (irc:RhodiumToad)