Re: TRM - Morbidity has set in, or not?

Dan wrote:
> Hi,
>
> Thanks for the response. I have a couple of follow-on questions.
>
> 1. "Not necessarily. The examples cited are rather small domains - a
> couple
> centuries worth of dates, states, words used in names or addresses -
> and
> the supported system would undoubtedly benefit by having these known
> ahead of time. But exhaustive enumeration isn't the only way one can
> specify a domain."
>
> Ok. Though understanding the alternative approaches to contrast to
> exhaustive enumeration would be useful, especially in light of the
> previous statement, "the values remain undisturbed and there's no need
> for index maintenance." Without enumeration, how does one claim that a
> set of values remain undisturbed?

In the illustration from which you plucked this fragment, the domains were enumerated.

> 2. "And CHAR (1000) is a trite example. How about JPEGs and MP3s and
> *.DOCs and XML."
>
> Let's stick with the trite example and demonstrate the effectiveness of
> the trite example first. Isn't this just a restatement of the age old
> claim that serialization of everything is the solution to everything.

Your turn: elaborate, please!

> Honestly, Claude Shannon covered this effectively and from an entirely
> theoretical perspective in the 60's.

And he said, ... What?

> 3. "Every domain should provide an operator that allows users to
> distinguish
> different values. If ordering is necessary: supply it. (And yes, TRM
> requires ordering; whether it is the same operator exposed to users is
> a different question, but I don't see any need for them to differ.) "
>
> This is an interesting and open question for me. It inevitably leads
> us back to whether domain and type are really the same thing. I tend
> to think not, and admittedly it runs against Date and many proponents
> here.

Sounds like an opportunity for a new topic.

   An equivalent or equal domain can have different ordering
> operators in my opinion and considering symbolic values independent of
> some operators provides a greater degree of independence.

How do "equivalent or equal" and "different ordering" work together?

> But I
> digress.

Yes, and...

> You wrote earlier that "TRM, on the other hand, would maintain exactly
> one ordered set of values for the domain." If we refer to that same
> ordered set but want an alternative ordering, we run into the same
> problems that lack of physical independence provides in network,
> hierarchical, and odbms data models, except that the problem might
> become more extreme because of the massiveness of potential domains.

...you seem to be trying to make some point about something that should simultaneously be "the same" and "different" and I'm not sure what that is.

> Don't get me wrong, I am not knocking the approach, but as with
> everything, it appears that this provides the set of
> benefit/shortcoming trade-offs that are dependent on context and on
> application that we've experienced before. It might not be a great
> "general" solution.

For some things, it might not be a great general solution. One difficulty with many computerizable solutions is that they're discrete representations of continuous systems. Obviously, there are going to be cracks; I think you touched on this earlier with the reference to symbolic values. Received on Wed May 17 2006 - 12:05:54 CEST