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how many Normalizations

Posted: Mon Nov 12, 2007 8:35 am
by qumar
hi,
how many Normalizations in mysql to create db. if you know any urls. please forward to me.
please help to me.
thanks,
qumar.

Posted: Mon Nov 12, 2007 11:20 am
by aceconcepts
It really depends on your database and data model.

Use a search engine to find example of how to normalise your tables - there are lots of tutorials out there.

Or

Give some more insight into your problem.

Re: how many Normalizations

Posted: Mon Nov 12, 2007 4:15 pm
by califdon
qumar wrote:hi,
how many Normalizations in mysql to create db. if you know any urls. please forward to me.
please help to me.
thanks,
qumar.
I'm not sure I know what you are asking. Normalization is a process that is used to help structure the tables of any relational database. Perhaps you are referring to the numbered Normal Forms defined by E.F. Codd and Chris Date in the 1960's. For a database to be reliable and efficient, it should meet the requirements of Second Normal Form, at a minimum. All that means is that your tables have no repeating fields or groups, and that all non-key fields are dependent on the primary key. Beyond that, there are several more Normal Forms, but there is no rule that says how "normalized" any database must be. It depends on a host of factors far too complex to permit a general answer. Here's a fairly good explanation of Normal Forms: http://trumpetpower.com/Papers/Normal_Forms

Posted: Tue Nov 13, 2007 5:28 am
by sunilbhatia79
I agree with califdon and aceconcepts... as a matter of fact at times (actually many times when doing MIS type of reporting and projects) you will have to denormalize your tables.

It all depends on the application that you develop and the trade off that you want to choose between speed v/s space.

Sunil