Rod Taylor <rbt(at)rbt(dot)ca> writes:
> Right now if the column exists in the child table, the add column is
> rejected. I assume that will remain.
Have you actually tried it?
regression=# create table p1 (f1 int);
CREATE TABLE
regression=# create table c1 (f2 int) inherits(p1);
CREATE TABLE
regression=# alter table p1 add column f2 int;
NOTICE: ALTER TABLE: merging definition of column "f2" for child c1
ALTER TABLE
regression=#
regards, tom lane