Re: comparing NEW and OLD (any good this way?) - Mailing list pgsql-general

    Sam Mason wrote:

> I've just realized another case where it's not consistent; why does the
> following return true:
>
>   SELECT row(null) IS NULL;
>
> and yet the following false:
>
>   SELECT row(row(null)) IS NULL;

You're intentionally assuming that row(null) IS NULL evaluating to true
implies that row(null) can be replaced by NULL. As discussed upthread, this
is not the case.

> I think I'm saying that PG should be deliberately breaking specified
> behavior and go back to pre-8.2 behavior in this regard.

But let's run your example with 8.1:

# SELECT row(null) IS NULL;
 ?column?
----------
 t

# SELECT row(row(null)) IS NULL;
 ?column?
----------
 f

These are the same results that you say are inconsistant, so pre-8.2 behavior
doesn't help here...

Best regards,
--
Daniel
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