> I have a small problem, and was wondering if there was a better fix than
> the one I have.
>
> Here goes: I have tables A and B, both with primary keys. A has a field
> which refers to rows of B, and vice versa. When these fields are modified,
> I want to ensure referential integrity, but without using triggers. Is it
> possible to avoid deadlock and preserve integrity in all situations
> without serializing the updates?
>
> Details: Without any locking, an update of A concurrent with a delete on B
> will cause an integrity breach. With locking, concurrent updates of A and
> B can cause a deadlock...
You cannot use a regular trigger because of your circular dependency. What you really need to insure integrity
is the FOREIGN KEY support coming with 7.0. It is implemented as triggers too, but they are handled a little
differentby the trigger manager and their execution can be delayed until COMMIT.
Jan
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