Re: [COMMITTERS] pgsql: Remove arbitrary ALTER TABLE .. ADD COLUMN restriction.

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Wed, Jan 26, 2011 at 10:36 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> This is not an "arbitrary restriction" because according to the SQL
>> standard those operations mean different things. In the first case you
>> get a column filled with the default value, in the second case you get a
>> column filled with nulls. And the latter case is the only one that
>> works properly with a rowtype.

> That's an untenable interpretation.

No, *your* interpretation is untenable. The sequence of operations that
the previous coding allowed behaves the same for both the table and
rowtype instances. The "shortcut" doesn't behave the same.

This was, I believe, discussed at length when the previous coding was
put in. The fact that you and Noah haven't read the spec carefully
doesn't give you license to change it.

regards, tom lane