Re: Add column if not exists (CINE)

Поиск
Список
Период
Сортировка
От Andrew Dunstan
Тема Re: Add column if not exists (CINE)
Дата
Msg-id 4BD828D6.5010304@dunslane.net
обсуждение исходный текст
Ответ на Re: Add column if not exists (CINE)  (Takahiro Itagaki <itagaki.takahiro@oss.ntt.co.jp>)
Ответы Re: Add column if not exists (CINE)
Список pgsql-hackers

Takahiro Itagaki wrote:
> Kjell Rune Skaaraas <kjella79@yahoo.no> wrote:
>
>   
>> I've been reading the earlier threads at:
>> http://archives.postgresql.org/pgsql-hackers/2009-05/thrd7.php#00252
>> http://archives.postgresql.org/pgsql-hackers/2005-10/thrd4.php#00632
>> and I'm not sure I have anything that substantially new to add but:
>>
>> I saw some indications that this might be a minority opinion,
>> well I would like to cast a vote FOR this functionality.
>>     
>
> +1 for CINE, just because MySQL supports it.
>   

MySQL compatibility has never been our aim. We should adopt ideas from 
other projects because they are good, not just because they are there.

That doesn't mean I don't think this is a good idea.

> But before developing, we need to decide how to handle an added object
> that has the same name but has different definitions. 
>   

The OP explicitly stated that in his opinion nothing should be done in 
such cases. That's a defensible position, in the case of objects such as 
tables that must be unique by name (e.g. tables).  But what would we do 
about objects where the name could be overloaded? Since we would 
presumably want to do this for all (or almost all) of our CREATE/ADD 
commands, we'd need a policy on those.
> Also, developers should consider not only ADD COLUMN but also other
> CREATE or ADD commands. The patch will be large, including documentation
> adjustments in many places -- it would be hard work.
>
>
>   

I can speak with some experience on this at least. :-) I don't see that 
it would be a heck of a lot bigger than the DROP IF EXISTS cases, which 
after the first few had been done were not hard, merely tedious to do :-)

cheers

andrew



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Fujii Masao
Дата:
Сообщение: Re: pg_start_backup and pg_stop_backup Re: Re: [COMMITTERS] pgsql: Make CheckRequiredParameterValues() depend upon correct
Следующее
От: Fujii Masao
Дата:
Сообщение: bug in build_startup_packet()