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

On Sun, Jan 24, 2010 at 8:36 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Sat, Jan 23, 2010 at 10:48 PM, KaiGai Kohei <kaigai(at)kaigai(dot)gr(dot)jp> wrote:
>> (2010/01/24 12:29), Robert Haas wrote:
>>> I don't think this is ready for committer, becauseTom previously
>>> objected to the approach taken by this patch here, and no one has
>>> answered his objections:
>>>
>>> http://archives.postgresql.org/pgsql-hackers/2010-01/msg00144.php
>>>
>>> I think someone needs to figure out what the worst-case scenario for
>>> this is performance-wise and submit a reproducible test case with
>>> benchmark results.  In the meantime, I'm going to set this to Waiting
>>> on Author.
>>
>> Basically, I don't think it is not a performance focused command,
>> because we may be able to assume ALTER TABLE RENAME TO is not much
>> frequent operations.
>
> I agree - the requirements here are much looser than for, say, SELECT
> or UPDATE.  But it still has to not suck.
>
> I think the problem case here might be something like this...  create
> ten tables A1 through A10.  Now create 10 more tables B1 through B10
> each of which inherits from all of A1 through A10.  Now create 10 more
> tables C1 through C10 that inherit from B1 through B10.  Now create
> 1000 tables D1 through D1000 that inherit from C1 through C10.  Now
> drop a column from A1.

Er... rename a column from A1, not drop.

...Robert