"PostgreSQL Bugs List" <pgsql-bugs(at)postgresql(dot)org> writes:
> create table test(f1 int4,f2 int4);
> insert into test (f1.f2) values (1,2);
> ERROR: cannot assign to a column of type integer because it is not a
> composite type
This diagnostic is not wrong. It might be a tad unhelpful, but I don't
think it's within the province of the parser to intuit that you meant to
type a comma instead of a period.
regards, tom lane