Re: Does Codd's view of a relational database differ from that ofDate&Darwin?[M.Gittens]

From: VC <>
Date: Thu, 16 Jun 2005 07:31:22 -0400
Message-ID: <>

"Alexandr Savinov" <> wrote in message news:42b14ba3$
> Jon Heggland schrieb:


>>>I understand your question: So what is the problem, we simply write
>>>queries and database engine executes them. Correct. But what if I do not
>>>want to write numerous queries? I want my database do it for me. I define
>>>only my data and then ask questions and that is all.
> Yes, we need to add more information into our model so that the database
> knows what to do if queries do not have enough information. In other
> words, the model has more information while queries are simpler.

Please explain what exactly you mean by the expression "the database knows what to do if the queries do not have enough information". 'Knows' in what sense ? As an AI specimen or in some other sense ? Also please give some specific examples of those queries illustrating your statement.

>>>RM is too low level mnodel and in this sense we are able to implement
>>>almost everything. The main problem is that the database itself (the
>>>model itself) is unaware of what we are doing, what we are implementing,
>>>what our data means, what is the purpose of some query.

In what specific way do you propose the database should be aware of "what we are doing" ?

> [...] Semantics can be defined as both constraints with data or only data.

No, it cannot. In your private vocabulary maybe.

> function applied to a set. It is more general - strictly speaking we can
> aggregate (project) everything and deproject everything.

What's 'project' and 'deproject' supposed to mean ?

Also, you still did not answer how the notion of 'singularity' and 'delta-function' is related to nulls. Eagerly awaiting.

> --
> alex
Received on Thu Jun 16 2005 - 13:31:22 CEST

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