Re: pointer to feature comparisons, please
| От | PFC |
|---|---|
| Тема | Re: pointer to feature comparisons, please |
| Дата | |
| Msg-id | op.ttwhjth2cigqcu@apollo13 обсуждение исходный текст |
| Ответ на | Re: pointer to feature comparisons, please (Ron Johnson <ron.l.johnson@cox.net>) |
| Ответы |
Re: pointer to feature comparisons, please
|
| Список | pgsql-general |
>>> The DELETE should block, no?
>> Why ?
>> Foreign keys put an ON DELETE trigger on the referenced table
>
> Foreign keys that silently, automatic DELETE records?
> Did I read that correctly?
Isn't that the point of ON DELETE CASCADE ?
>> besides checking the referencing column on insert/update... If you just
>> implement a constraint, you only get half the functionality.
>
> But when I define a FK *constraint*, that's all I *want*!
When you add a REFERENCE foo( bar ) foreign key and don't specify ON
DELETE clause, I believe you get ON DELETE NO ACTION, which means the
referenced row can't be deleted if there are referencing rows... so when
you have a FK constraint, it actually constrains two tables, and pg uses
share locking to ensure race conditions can't cause an inconsistent
database.
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