Re: add column .. default

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Rod Taylor <rbt(at)rbt(dot)ca>
Cc: Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl>, PostgreSQL Development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: add column .. default
Date: 2003-06-19 14:42:52
Message-ID: 8726.1056033772@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Rod Taylor <rbt(at)rbt(dot)ca> writes:
> On Thu, 2003-06-19 at 10:05, Alvaro Herrera wrote:
>> Sorry, I haven't read the spec, but what happens when there is a default
>> value already and it's not NULL? Are tuples where column =3D default
>> updated? Are tuples where column IS NULL updated?

> We're talking about add column. Since it's a new column, there will
> never be a default and all entries are NULL in PostgreSQL.

That's an overly simplistic analysis, given that the column may already
exist in child tables. I am not sure that the behavior is fully
consistent even now in such cases, but we at least should make certain
it doesn't become less consistent.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Rod Taylor 2003-06-19 14:53:36 Re: add column .. default
Previous Message Rod Taylor 2003-06-19 14:34:30 Re: Two weeks to feature freeze