Jeff Davis <pgsql(at)j-davis(dot)com> writes:
> There's no single test, but you can see if it's an empty row with:
> x IS NULL AND x IS DISTINCT FROM NULL
> And you can see if it's a "real" NULL by:
> x IS NULL AND x IS NOT DISTINCT FROM NULL
Hmmm ... that suggests that we may not be handling IS DISTINCT FROM
correctly for rowtypes. I haven't read that part of the spec, but
I would've guessed that the spec wants it to be consistent with
IS NULL.
regards, tom lane