Re: What are Closing and Normalization?

I have not heard the term Closeing?

It perhaps may have some meaning in a particular context, but as a general term..hum? By closing..it would not mean when we "close" Excel to save our data would it?

The next term:Normalization

I will give you a blurb:

Normalization is a complex process with many specific rules and different levels intensity. In its full definition, normalization is the process of discarding repeating groups, minimizing redundancy, eliminating composite keys for partial dependency, and separating nonkey attributes.

In simple terms, the rules for normalization can be summed up in a single phrase: "Each attribute (column) must be a fact about the key, the whole key, and nothing but the key." Said another way, each table should describe only one type of entity (such as a person, place, customer order, or product item).

So, what does all that mumbo-jumbo mean at the end of the day?

Well, when you use products like Excel, the "cost" of adding a new column is very cheap. You need a new column for a sales month in Excel, you simply add the column the new column called Jan2003 (this month).

In a database is it VERY EXPENSIVE TO ADD a new column. It is super cheap to add a new record (a row). The reason for such a big difference between Excel (which does not in general have normalized data) and a database is:

To add a new column in a database means all your reports, data entry screens and even code now has to be changed. Imagine a system where you spend a full year developing the system, and then you realize that you now much add a new field! In Excel, there is little, or no consequence to add a new column for the sales month. In a database, that is big disaster. Every single screen, report etc that uses the table will have to be modified when you add a new column (field) to that table.

So, simply put, normalizing lets us built something like an accounting system,
and we don't have to modify the code, or the application for every new customer, or account number we enter. If the system was not normalized, then the accounting software would be of no use. In other words, no code, or tables STRUCTURES needs to be modified to run the accounting system.

There is a zillion articles on this topic

Fire up a goggle search engine..

http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B100139

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Albert D. Kallal
Edmonton, Alberta Canada
kallal_at_msn.com
www.attcanada.net/~kallal.msn