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Re: 1 NF

From: Cimode <cimode_at_hotmail.com>
Date: 1 Mar 2007 00:39:44 -0800
Message-ID: <1172738384.669560.170240@j27g2000cwj.googlegroups.com>


On Feb 28, 10:12 pm, Sampo Syreeni <d..._at_iki.fi> wrote:
> On 2007-02-28, Cimode wrote:
> > The answer is NOT A CHANCE as BLOBS break the primary requirement of
> > independence between logical and physical layer and the fact that a
> > BLOB attribute included in any proposition can not make a relation out
> > of it (1NF dictates that all information MUST be stored as relations)
>
> ...and it is. A blob is simply a member of the set of strings of
> integers in the range [0,255]. If you can have attribute values drawn
> from strings over a finite (enumerated) set of characters, surely you
> can have attribute values drawn from strings over a finite set of plain
> integers.

A blob (binary large objet) is a physical implementation on direct image systems that stores direct views of binary filed non natively in the dbms therefore it is nothing more but a physical implementation. 1NF qualification of a schema is a purely logical concept. Anything more added would be superfluous. For more information, read Introduction to databases systems - CJ DATE ...He explains quite precisely the difference between physical, logical and user view layers....

Hope this helps...

> So, please elaborate.
> --
> Sampo Syreeni, aka decoy - mailto:d..._at_iki.fi, tel:+358-50-5756111
> student/math+cs/helsinki university,http://www.iki.fi/~decoy/front
> openpgp: 050985C2/025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
Received on Thu Mar 01 2007 - 02:39:44 CST

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