Re: Deferred constraints performance impact ?

On Fri, Jul 20, 2012 at 4:27 AM, mark <dvlhntr(at)gmail(dot)com> wrote:
> We have put some deferred constraints (some initially immediate, some
> initially deferred) into our database for testing with our applications.

> I understand a lot more may have to be tracked through a transaction and
> there could be some impact from that. Similar to an after update trigger? Or
> are the two not comparable in terms of impact from what is tracked and then
> checked.

Another factor might be the amount of constraint violations you
expect: if there are many then deferring the check can create much
more work for the DB because you issue more DML as with a non deferred
constraint which could create errors much sooner and hence make you
stop sending DML earlier.

Kind regards

robert

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