Re: [BUG?] strange behavior in ALTER TABLE ... RENAME TO on inherited columns

KaiGai Kohei <kaigai(at)kaigai(dot)gr(dot)jp> writes:
> (2009/12/30 10:38), Robert Haas wrote:
>> No longer applies. Can you rebase?

> The attached patch is the rebased revision.

I'm not really impressed with this patch, because it will reject
perfectly legitimate multiple-inheritance cases (ie, cases where there's
more than one inheritance path from the same parent). This works fine
at the moment:

regression=# create table p1(f1 int, f2 int);
CREATE TABLE
regression=# create table c1(f3 int) inherits (p1);
CREATE TABLE
regression=# create table c2(f4 int) inherits (p1);
CREATE TABLE
regression=# create table cc(f5 int) inherits (c1,c2);
NOTICE: merging multiple inherited definitions of column "f1"
NOTICE: merging multiple inherited definitions of column "f2"
CREATE TABLE
regression=# \d cc
Table "public.cc"
Column | Type | Modifiers
--------+---------+-----------
f1 | integer |
f2 | integer |
f3 | integer |
f4 | integer |
f5 | integer |
Inherits: c1,
c2

regression=# alter table p1 rename f2 to ff2;
ALTER TABLE
regression=# \d cc
Table "public.cc"
Column | Type | Modifiers
--------+---------+-----------
f1 | integer |
ff2 | integer |
f3 | integer |
f4 | integer |
f5 | integer |
Inherits: c1,
c2

I don't think that protecting against cases where things won't work
is an adequate reason for breaking cases that do work.

regards, tom lane