Ð ÐÑÐ, 18.08.2004, Ð 04:45, Josh Berkus ÐÐÑÐÑ:
> Markus,
Hi Josh,
> Hey, I see you figured out a workaround to writing a trigger for this. Let's
> see if we can make it work.
>
> ERROR: there is no unique constraint matching given keys
> for referenced table "objects"
>
> The reason for this is that CASCADE behavior gets quite odd when there is an
> FK reference to a non-unique column. We used to allow it, in 7.1, and I was
> responsible for a number of bug reports that led to us disallowing it. It
> should be theoretically implementable and relationally sound but will require
> a *lot* of troubleshooting to make work. So far, nobody's really interested
> enough.
>
> However, you have an easy way out:
>
> ALTER TABLE objects ADD CONSTRAINT obj_unq_2 UNIQUE (name, class_name);
I was worried about the performance hit because (name, class_name) will
always be unique, yet they will be checked for uniqueness.
Thanks
--
Markus Bertheau <[EMAIL PROTECTED]>
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faqs/FAQ.html
