There is one further argument for user classes as primary keys -
type checking. I believe this to be an important consideration.
tim
> > From: A mailing list for Enterprise JavaBeans development
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Tinou Bao
>
> > if your primary key is not a compound key but just a simple int or long is
> > there any reason to define your own pk class instead of just using the
> > String class or Long class? does it have anything to do with how well the
> > hashcode is distributed?
>
> No, since typically, if your PK class is a simple wrapper over a long, you
> will return this value as your hashCode.
>
> The following arguments can be said for user classes as primary keys:
>
> - they make it easier to move to a compound primary key implementation if
> one day, you decide you need it (less search/replace through your code, and
> you are already using real objects instead of primitive ones, i.e. calling
> equals() for comparison, etc...)
>
> - they represent an overhead compared to primitive types
>
> For primitive types as primary keys, just reverse those points.
>
> My recommendation? Premature optimization is the root of all evil: start
> with a user primary key class, even if all it does is wrap a primitive type.
> Revert to a primitive type if ever you find out after careful profiling that
> it is causing a big slow down in your application. Chances of that
> happening are very slim, though, you will find that there are a lot of other
> factors that need to be taken care of first.
>
> --
> Cedric
>
> ===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> of the message "signoff EJB-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
>
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
