Re: Problem with FK referential actions

Stephan Szabo wrote:
> The output from the select, should I believe be (3,1), (4,1)
> not (4,1), (4,1). I think we're violating General Rule 4 (I think
> that's it) on the referential constraint definition ("For every
> row of the referenced table, its matching rows, unique matching
> rows, and non-unique matching rows are determined immediately
> before the execution of any SQL-statement. No new matching
> rows are added during the execution of that SQL-statement.")
> because when the update cascade gets done for the 2 row, we've
> changed the (2,1) to (3,1) which then gets hit by the update
> cascade on the 3 row.
>
> I was wondering if you had any thoughts on an easy way around
> it within what we have. :)

I think you're right in that it is a bug and where the
problem is. Now to get around it isn't easy. Especially in
the deferred constraint area, it is important that the
triggers see the changes made during all commands. But for
the cascade to hit the right rows only, the scans (done with
key qualification) would have to be done with a scan command
counter equal to the original queries command counter.

The old (more buggy?) behaviour should've been this annoying
"triggered data change violation". But some folks thought
it'd be a good idea to rip out that bug. See, these are the
days when you miss the old bugs :-)

Jan

--

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