Re: pointer to feature comparisons, please
От | PFC |
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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
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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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