Re: WWW/Internet 2009: 2nd CFP until 21 September

From: paul c <>
Date: Mon, 10 Aug 2009 17:38:44 GMT
Message-ID: <EWYfm.38505$Db2.1948_at_edtnps83>

Walter Mitty wrote:
> "paul c" <> wrote in message
> I can't pin down the page. Here's the relevant quote.
> quote:
> The simplicity of the array representation which becomes feasible when all
> relations are cast in normal form is not only an advantage for storage
> purposes but also for communication of bulk data between systems which use
> widely different representations of the data. The communication form would
> be a suitably compressed version of the array representation and would have
> the following advantages:
> (1) It would be devoid of pointers (address-valued or displacement-valued )
> .
> (2) It would avoid all dependence on hash addressing schemes.
> (3) It would contain no indices or ordering lists.
> unquote:
> It is, of course my interpretation that the above anticipates the kind of
> data in transit that I alluded to in my OP. I think it's a reasonable
> interpretation. I may hear other opinions in the course of this discussion.

Thanks. Earlier on he says this:

"An array which represents an n-ary relation R has the following properties :

(1) Each row represents an n-tuple of R.
(2) The ordering of rows is immaterial.
(3) All rows are distinct.
(4) The ordering of columns is significant-it corresponds
to the ordering S1, Sz , . . . , S, of the domains on which R is defined (see, however, remarks below on domain-ordered and domain-unordered relations ) .
(5) The significance of each column is partially conveyed by labeling it with the name of the corresponding domain."

Although he doesn't use the term "named relation" in this quote, it does seem he was talking about a communication arrangement ("representation") as well as a storage arrangement, in a sense they are basically the same thing. Given that users agree on a "predicate", the meaning of such an array would be immediately recognizable. In 1999 the xml proponents claimed to write about a seemingly "new" distinction between format and meaning! It seems that Codd presaged them by about thirty years! In his paper, he fairly easily dismissed with "nesting" that the xml people think is essential for any arrangement of data. Received on Mon Aug 10 2009 - 19:38:44 CEST

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