Query regarding normalization of the relations

Question

I am given a case study of Event Management to develop an ER model and based on it its normalization forms and relational schema. Now i have developed my ER Model based on the SRS that i have developed. Now the question that i am having is when i converted my ER diagram to the relational schema i got my tables already normalized. Because of the ER diagram i had nothing to do more in normalization process so i got confused.

Now the question arose in my mind is whether or not it is desirable situation? I mean when i am getting my all the relations normalized from the ER diagram itself then why do i need to do normalization at all?

Answer 1

If your tables are already in 5NF then you don't need to think much more about further normalization.

Note however that the principle of full normalization (POFN) is no panacea. There may remain non-obvious update anomalies.

Database constraints will need to be applied. In my experience, designers who start with an ER diagram are great at implementing primary keys and foreign keys but other constraints can be easily overlooked. Other design approaches may result in better constraints e.g. I have a little experience of object role modelling which seemed to work well.

Further normalization should only be considered in conjunction with constraints because 6NF often makes constraints more difficult to implement using today's industrial-strength technologies e.g. none support Standard SQL's CREATE ASSERTION nor CHECK constraints that may include a subquery.

Also consider the principle of orthogonal design (POOD).