Subject: RE: QDIM issue: the SchedulingService classes

From: "Weiss, Walter" <[email-masked]>
Date: Tue, 22 Aug 2000 13:28:42 -0400

Andrea,

-----Original Message-----
From: Andrea Westerinen [mailto:[email-masked]]
Sent: Tuesday, August 22, 2000 12:39 AM
To: Weiss, Walter; 'Andrew Smith'
Cc: [email-masked]; [email-masked]
Subject: RE: QDIM issue: the SchedulingService classes

Please note that modeling using a table is not "good" OO practice.  Tables
exist either because you have multiple instances of something (best done as
a class with instances) or because you want to relate the rows and columns
and put some data at the right spot in the table.  The latter is really an
implementation dependent way of modeling an association.  There are always
two perspectives to a "relate the rows and columns" table - in this case,
the rows and columns represent queues and schedulers.  The data at the
intersection of the row and column is specific to BOTH the queue and the
scheduler - so, it is best modeled as an association.
 
<Walter> Most everything in a router is implemented in tables. Filters,
Meters, Markers, Routing entries, MAC addresses, VLANs, VCs, and Security
Associations are just a few of the structures that come to mind that are
typically in tables. All of these meet your criteria of being indexed in two
directions. Are you saying that all of these need to be represented in
associations?

regards,

-Walter

---

From: "Andrea Westerinen" <[email-masked]>
Date: Tue, 22 Aug 2000 10:46:26 -0700

RE: QDIM issue: the SchedulingService classesI do not understand your
statement that a table of Filters or MAC addresses is indexed in two
directions.  A Filter or MAC address is an instance of a class in an info
model.  Where there are relationships (for example, grouping a bunch of
filter entries into a filter list, or tieing a filter list to a
Classifier) - these should be represented in the info model as associations.

How any of these concepts are implemented is up to the data model.  In the
data model, you make the determination whether you use associations, tables,
arrays or something else.

Andrea

-----Original Message-----
From: Weiss, Walter [mailto:[email-masked]]
Sent: Tuesday, August 22, 2000 10:29 AM
To: 'Andrea Westerinen'; 'Andrew Smith'
Cc: [email-masked]; [email-masked]
Subject: RE: QDIM issue: the SchedulingService classes

Andrea,
  -----Original Message-----
  From: Andrea Westerinen [mailto:[email-masked]]
  Sent: Tuesday, August 22, 2000 12:39 AM
  To: Weiss, Walter; 'Andrew Smith'
  Cc: [email-masked]; [email-masked]
  Subject: RE: QDIM issue: the SchedulingService classes

  -Walter