Re: Add column and specify the column position in a table

Поиск
Список
Период
Сортировка
От Andrew Sullivan
Тема Re: Add column and specify the column position in a table
Дата
Msg-id 20060518155829.GE29472@phlogiston.dyndns.org
обсуждение исходный текст
Ответ на Re: Add column and specify the column position in a table  ("Guillaume Lelarge" <guillaume.lelarge@gmail.com>)
Ответы Re: Add column and specify the column position in a table  ("Guillaume Lelarge" <guillaume.lelarge@gmail.com>)
Список pgsql-sql
On Thu, May 18, 2006 at 05:43:19PM +0200, Guillaume Lelarge wrote:
> Do you mean that, using "alter table test add column" with the "after"
> option, MySQL creates a new table, populates it with the old table
> data and finally drops the old table ? I mean, there's the same
> performance problem with big tables ?

MySQL does that for a great deal of its DDL.  Yes, the performance is
awful for this on big tables.

The reason I didn't answer the OP's question, though, is that I can't
think of a legitimate reason to do this anyway.  The physical layout
of the columns should not be of concern to the developer, who should
be naming the columns anyway.

A

-- 
Andrew Sullivan  | ajs@crankycanuck.ca
The whole tendency of modern prose is away from concreteness.    --George Orwell


В списке pgsql-sql по дате отправления:

Предыдущее
От: "Guillaume Lelarge"
Дата:
Сообщение: Re: Add column and specify the column position in a table
Следующее
От: Markus Schaber
Дата:
Сообщение: Re: Constraint question