FOREIGN KEY !!!!!

We got a little dispute in the FKEY project :-)

In section 11.9, the SQL3 draft explicitly discribes what to
do for referential actions ON DELETE and ON UPDATE. First
there seems to be an incompatibility between SQL3 and SQL-92.
While Date describes and Oracle implements NO ACTION to raise
an exception if a PK delete leaves an unsatisfied foreign
key, the SQL3 specs explicitly define that behaviour for the
RESTRICT action.

Second, there's absolutely nothing said about anything to do
for NO ACTION in SQL3. Thus, our current implementaion in
fact doesn't do anything meaningful. That makes it totally
legal, to delete a PK leaving an unsatisfied FK behind,
resulting in an in fact violation. And NO ACTION is the
default if no referential actions given explicitly in the
schema.

Don Baccus now suggested, to interpret NO ACTION as "if it
would result in a violation, then silently rollback this
update for the PK row in question". Not to speak about the
technical problems arising from an attempt to do so, but as
said, such a behaviour is nowhere mentioned in the SQL3
draft. OTOH it would close the possible violation hole in
our implementation of FOREIGN KEY.

What do others think about it? We need a decision urgent, or
going for the suppress/rollback will cause a release delay,
definitely.

Jan

--

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