Subject Re: [firebird-support] Re: extract constraint from Domain
Author Alexandre Benson Smith
Ann W. Harrison wrote:

>Not true, unfortunately. The foreign key is evaluate in the system
>transaction context. Triggers are evaluated in the user transaction
>context. A foreign key constraint will fail if two concurrent
>transactions make changes that invalidate the constraint.
>Consider the case that occurs when one transaction attempts to delete
>a record from the referenced table that has no matching committed
>records in the referencing table while a concurrent transaction stores
>a record in the referencing table that matches the record being deleted.
>A foreign key constraint will detect and stop the inconsistent result.
>Triggers on the two tables will not.

I am sure it was asked a bunch of times... But since I don't remeber any
answer for this, I will ask it again (pardon me if it is repetitive).

But there is any reason let the user specify some option to do a "dirty
read" to make possible to the triggers to run in a system like transaction ?

see you !

Alexandre Benson Smith
THOR Software e Comercial Ltda
Santo Andre - Sao Paulo - Brazil