Re: [COMMITTERS] pgsql: Remove arbitrary ALTER TABLE .. ADD COLUMN restriction. - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [COMMITTERS] pgsql: Remove arbitrary ALTER TABLE .. ADD COLUMN restriction.
Date
Msg-id 16000.1296056161@sss.pgh.pa.us
Whole thread Raw
Responses Re: [COMMITTERS] pgsql: Remove arbitrary ALTER TABLE .. ADD COLUMN restriction.  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <rhaas@postgresql.org> writes:
> Remove arbitrary ALTER TABLE .. ADD COLUMN restriction.
> The previous coding prevented ALTER TABLE .. ADD COLUMN from being used
> with a non-NULL default in situations where the table's rowtype was being
> used elsewhere.  But this is a completely arbitrary restriction since
> you could do the same operation in multiple steps (add the column, add
> the default, update the table).

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.

Kindly revert this patch.
        regards, tom lane


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: Extensions support for pg_dump, patch v27
Next
From: David Fetter
Date:
Subject: Re: Seeking Mentors for Funded Reviewers