4.25

Suppose a user creates a new relation r1 with a foreign key referencing another relation r2. What authorization privilege does the user need on r2? Why should this not simply be allowed without any such authorization?

---

The references privilege needs to be granted to the user on the relation r2. This should not be allowed without any such authorization because, foreign-key constraints restrict deletion and update operations on the referenced relation. That is, operations such as update and delete on r2 may bring changes to r1 as well.