Re: Number of attributes in HeapTupleHeader

Поиск
Список
Период
Сортировка
От Hiroshi Inoue
Тема Re: Number of attributes in HeapTupleHeader
Дата
Msg-id 3CD736E4.D07A2686@tpf.co.jp
обсуждение исходный текст
Ответ на Number of attributes in HeapTupleHeader  (Manfred Koizar <mkoi-pg@aon.at>)
Список pgsql-hackers
Rod Taylor wrote:
> 
> I think the real trick is keeping track of the difference between:
> 
> begin;
> ALTER TABLE tab ADD COLUMN col1 int4 DEFAULT 4;
> commit;
> 
> and
> 
> begin;
> ALTER TABLE tab ADD COLUMN col1;
> ALTER TABLE tab ALTER COLUMN col1 SET DEFAULT 4;
> commit;
> 
> The first should populate the column with the value of '4', the second
> should populate the column with NULL and have new entries with default
> of 4.

I know the difference. Though I don't love the standard
spec of the first, I don't object to introduce it.
My only anxiety is that the implementation of the first
would replace the current implementaion of ADD COLUMN
(without default) together to touch tuples.

regards,
Hiroshi Inouehttp://w2422.nsk.ne.jp/~inoue/


В списке pgsql-hackers по дате отправления:

Предыдущее
От: "Christopher Kings-Lynne"
Дата:
Сообщение: Re: Set Returning Functions (SRF) - request for patch review and comment
Следующее
От: Mark kirkwood
Дата:
Сообщение: Unbounded (Possibly) Database Size Increase - Test Case