Re: cdt glossary 0.1.1 [MV]
Date: Thu, 19 Apr 2007 01:12:58 +0200
Message-ID: <4626a551$0$323$e4fe514c_at_news.xs4all.nl>
Mike Preece wrote:
Hi Mike,
Did you really have to quote the whole of the glossary to make us all
of scrolling like crazy?
(Answer: no you didn't. Oh well.)
>> [MultiValue, MV]
>> 1. One name for the industry surrounding the Nelson-Pick data model.
>> In this context:
>> FILE: a real-world collective noun.
>> RECORD: a real-world object.
>> FIELD: is a real-world adjective.n.
>>
>> 2. A data field (or attribute) defined to permit a variable number of
>> values as a list (array).
>
> I think the context given for 1. above is less than helpful. In
> keeping with the quote from Date above: "The entire information
> content of a relational database is represented in one and only one
> way: namely, as attribute values within tuples within relations",
> perhaps:- "The entire data content of a MV/Pick database is
> represented as (delimited) strings: namely as zero or more subvalues
> within multivalues within attributes (or "fields") within items (or
> "records") within files". Also, 2. above is imprecise, if not
> incorrect. Better: "A multivalue is one of the multiple values of an
> attribute and can itself contain 0 or more subvalues".
You may very well be right. However, the purpose of the glossary is /not/ to push home one view on c.d.t. (one admit I subscribe to: RM is the best we have for DM thus far) - it is just to shortcut misunderstandings because of identifiable different interpretations.
Dawn is our recognized MV expert, so if she agrees ... :-) Received on Thu Apr 19 2007 - 01:12:58 CEST