BUG #17101: Inconsistent behaviour when querying with anonymous composite types

On Monday, July 12, 2021, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Andrew Kiellor <akiellor(at)gmail(dot)com> writes:
> > Sorry I omitted the output. It is as follows:
>
> > psql:test.sql:14: ERROR: input of anonymous composite types is not
> implemented
> > LINE 1: SELECT * FROM table1 WHERE column1 = '(0)';
> > ^
>
> I think this is operating as designed. I agree it'd be slightly more
> convenient if the parser would infer that the RHS must be of the same
> type as the LHS, but shoehorning that into the existing system design
> seems problematic.
>
>
Why is the multi-valued IN expression special here? I would not expect the
more-than-one element IN clause to obey different rules than a one element
IN clause

-- passing scenario - IN query with multiple anonymous composite types
SELECT * FROM table1 WHERE column1 IN ('(0)', '(0)');

David J.