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Re: Object Class and Data Type

From: Neo <neo55592_at_hotmail.com>
Date: 1 Apr 2004 21:49:38 -0800
Message-ID: <4b45d3ad.0404012149.444809d1@posting.google.com>


> > > ... one never sees data type, a base type, defined as a data type!
> >
> > It is difficult to see and implement this in RDM because
> > it's lowest fundamental unit of abstraction (aka relation)
> > doen't go low enough.
>
> Since relation headings are composed of attributes,
> each of which has a type, it makes no sense to say that
> "it's lowest fundamental unit of abstraction" is the relation.

If we agree the "type" of int, char, str, etc is "thing", then we can start to model it as follows:

T_Thing
1 int
2 char
3 str

But the attributes in T_Thing itself have a type (ie int, str), so how does one relate the row's ID to the T_Thing's attribute types? If one uses another table, then how does one relate that table's attribute types to rows in T_Thing. This problem is recursive and can't be represented properly within RDM. If you think otherwise, could you show a schema that would.

Also would you agree that RDM has a "fundamental unit of abstraction"? If so what would it be? Received on Thu Apr 01 2004 - 23:49:38 CST

Original text of this message

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