Re: Searching OO Associations with RDBMS Persistence Models

Dmitry A. Kazakov wrote:
> On 16 Jun 2006 13:03:30 -0700, Aloha Kakuikanu wrote:
>
> > Robert Martin wrote:
> >> A logical connection between two endpoint is a list of circuits. This
> >> application object is transient because the connections come and go.
> >> They aren't stored in the database.
> >
> > Assume network is an [indirected] graph.
>
> Directed (consider ADSL, RFID etc)
>
> > Then logical connection is a
> > path in the graph.
>
> No. That's routing issues. A connection is either peer-to-peer or
> multicast. It does not mention any nodes passed. Some protocols use dynamic
> routing.

OK. Now please explain what RM meant by
"A logical connection between two endpoint is a list of circuits"

> > There is nothing challenging in modelling graph in
> > RDBMS and creating application objects that correspond to paths in a
> > graph.
>
> Incidence matrix? Huh.
>
> > Why "object id" is significant in this picture? |
>
> Because an object can be mobile. Connection can obviously be described by a
> trivial relation between nodes. But it is an implementation detail in, say,
> a middleware, which deals with objects, not connections.

OK. Now please explain why this elusive "object id" can't be a key of some tuple. I even suggest a name for this relation: ConnectionNode. Received on Mon Jun 19 2006 - 06:03:14 CEST