Re: Codd provided appropriate mathematics ... (was Re: Relational and MV (response to "foundations of relational theory"))

Home -> Community -> Usenet -> comp.databases.theory -> Re: Codd provided appropriate mathematics ... (was Re: Relational and MV (response to "foundations of relational theory"))

From: Marshall Spight <mspight_at_dnai.com>
Date: Wed, 10 Mar 2004 04:39:02 GMT
Message-ID: <GZw3c.222806$jk2.860097@attbi_s53>

"Bob Badour" <bbadour_at_golden.net> wrote in message news:l-mdnVu0ycQQGdPdRVn-vA_at_golden.net...
>
> I have no particular use for lists at the logical level.

Really? You never have arbitrarily ordered data?

> >
> > So you're thinking of a view which produces the compression?
>
> No, I am thinking of compression as a physical issue unrelated to the
> logical interface.

I can see how that can work with lossless compression, but I don't see how it can work with lossy compression. Lossy compression has uservisible effects. It is therefor a logical issue, not a physical one.

Lame example: RLL encoding in a GIF can be completely automatic and exist only at the physical level. JPEG encoding needs user-visible controls, and has to be visible at the logical level.

Marshall Received on Tue Mar 09 2004 - 22:39:02 CST