Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp> writes:
> In my understanding below row value constructors(I hope this term is
> correct) exaples should return true, but PostgreSQL does not.
By my reading, a "row value constructor" is one of the things in
parentheses, while the whole clause is a "comparison predicate"
(per section 8.2 of SQL92). But I agree that we don't seem to
have implemented the semantics correctly. The code currently
responsible for this is makeRowExpr() in gram.y ... I tend to
agree with the comment on it that says that the functionality
should be pushed deeper ...
regards, tom lane