[Informatics] Data normalisation

[Robert Hind]

Well Litsa you did send the ppt files to all of us and I was interested
enough to have a look at the example file.
 
Now I must take exception to slides 26 and 27 - pics below
 
Both the statements on yellow background are false. The HouseColor depends
only on the HouseName (or vice versa), not directly on the StudentID.
 
As almost noted in slide 28 " These two non-key fields are more dependent on
each other than they are on the primary key"
 
The key 3NF rule here is: "remove to a new table any non-key attributes that
are more dependent on other non-key attributes than the table key"
 
So we move HouseName and HouseColor to a new table and leave just HouseName
in the Student table.
 
Robert Hind
Ex Traralgon and Ashwood
Retired
 



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From: informatics-bounces at edulists.com.au
[mailto:informatics-bounces at edulists.com.au] On Behalf Of Litsa Tzelepis
Sent: Tuesday, 4 October 2016 2:54 PM
To: Year 12 VCE Informatics Teachers' Mailing List
Subject: [Informatics] Data normalisation




-- 

Litsa Tzelepis
Mount St. Joseph Girls' College
133 Maidstone Street, Altona, VIC. 3018
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