>>> 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.