Re: An object-oriented network DBMS from relational DBMS point of view

Drago Ganic wrote:

> Hi,
> I do not agrre with the definition "instance of ADT" = object." nor do I
> think that object is not well defined.
>
> Look up the book "Structure and Interpretation of Computer Programs" (SICP
> for short) by Ableson and Sussman.
>
> The right name for "instance of type (or ADT)" is *value* and not *object*.
>

Except that many use the word "object" to mean "value" too. That the same folks use "object" to mean "variable" and "type" doesn't help.

[snip]

> On the other hand, I don't think that object is (so) vague defined. Its
> definition includes identity and state that can be changed (like a classical
> typed variable from the above example).

Thus, you define "object" to mean "variable", but we already have a word that means "variable". What's the point of having the synonym?

[snip]

> So, IMO object/class is well defined.

Um, no. What you have done is specify a definition. However, that definition simply makes the word redundant and most of the people who use the word do not limit themselves to that definition.

> But, in the region of RM I prefer the term entity instead of object as Chen
> has thought us. Entities have also identity (inside a particular entity
> type) and they are trivially mapped to Relations.

Ugh. Why do so many people cling to artificial, fictitious distinctions? They are trivially mapped because they were relations to begin with--you just gave some of your relations a new name.

[snip]

> P.S.: I personally differentiate between code and data. To me data is like
> mass in physics. It is static and has structure. I move it around, destroy
> it etc.

I suggest you find a way to check out the standard vocabularies. One can move code, and in fact "code motion" is an important concept. One can destroy it, create it etc. While code and data have very different meanings, the above nonsense is just nonsense.

[snip] Received on Sun Mar 18 2007 - 15:04:15 CET