Oracle triggers = poor performance ??

I've heard Oracle triggers really impact performance. I'm using ErWin and am trying to decide if I should use triggers to enforce RI in addition to my foreign key constraints. With triggers, for example, I have the ability to cascade, restrict or orphan child nodes when a parent is either inserted, updated, or deleted. Can I get that flexibility with keywords off of the constraints (e.g. cascade delete)???

Here's a typical cascade delete trigger: (table address has two children, useraddress and propertyaddress)

Thoughts????

thx in adv.
-Ed

declare numrows INTEGER;
begin

/* ERwin Builtin Thu Jul 29 13:47:02 1999 */
/* Address R/268 UserAddress ON PARENT DELETE CASCADE */
    delete from UserAddress

      where
        /*  %JoinFKPK(UserAddress,:%Old," = "," and") */
        UserAddress.AddressID = :old.AddressID;

/* ERwin Builtin Thu Jul 29 13:47:02 1999 */
/* Address R/266 PropertyAddress ON PARENT DELETE CASCADE */
    delete from PropertyAddress

      where
        /*  %JoinFKPK(PropertyAddress,:%Old," = "," and") */
        PropertyAddress.AddressID = :old.AddressID;

• ERwin Builtin Thu Jul 29 13:47:02 1999 end;