Friday, February 24, 2012

Is there any guideline to reach the 5NF or above in database designing?

Dear All,

How to reach to the highest level of normalization for database designing?

Guide Lines Needed.

What will be the characteristics of a database of a completely normalized databae?

Check List needed.

Thanks

SuryaPrakash Patel

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*****************************************>> How to reach to the highest level of normalization for database
>> designing?

Classical normalization mandates the highest level as 5NF/PJNF which can be
achieved by applying non-loss decomposition by the relational projection
operator. In the late seventies, IBM researcher Ron Fagin has determined
that this is both necessary and sufficient to eliminate any update/insert
anomalies.

>> Guide Lines Needed.

Get a book on the subject. Newsgroups are a poor source for data design
principles since poor advice from pseudo experts is rampant & segregating
chaff from good stuff can be hard.

>> What will be the characteristics of a database of a completely normalized
>> databae?

As mentioned before, fully normalized databases are devoid of update/insert
anomalies.

However, normalization by itself alone, does not guarantee a redundancy-free
database. Other kinds of logical flaws could exist which prompted researches
to propose other design guidelines like Date/McGoveran's New Design
Principle etc. Back in 2001, Tom Johnston wrote a 5-part article in DM
Direct about certain unobvious redundancies with derived attributes,
"formula"-based redundancies, relationship redundancy due to lack of
semantic constraints etc. which are undesirable, but cannot be eliminated by
normalization process alone. (
http://www.dmreview.com/authors/aut...?AuthorID=30923 ).

Also sometime back Date had an article Normalization Is No Panacea in
DBPD, but I do not remember the content exactly.

>> Check List needed.

Use decent books due to previously stated reason. I recommend T. J. Teorey &
C. J. Date, but there are other good ones too.

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Anith|||Thank you very much...

Please suggest the book name(s) if you have any idea to solve this problem of database designing,,
Thank you again

SuryaPraksh

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