I can support Razzak's suggestion. The dependency viewer showed me some
not so obvious boo-boos in a database I am working with. It is a great tool.
Albert
On 22/02/2012 5:25 PM, A. Razzak Memon wrote:
At 11:26 AM 2/22/2012, Bill Downall wrote:
If you do not normalize, and you provide room for 3 phone numbers,
some day you will have to put the fourth phone number in the
comments, or change the schema to allow for 4 phone numbers.
Schema changes are expensive, because all forms and reports and
procedures and eeps and views and rules and triggers and applications
that relate to that data may have to be changed, too, and cannot be
done by users through "settings", but have to be done by programmers.
Putting the data in the "wrong" place like the comments means people
won't find that data with a normal search or query.
There are other good reasons to normalize, like not "wasting" columns
that are usually blank, and not having to search three or five
columns instead of one (For example, to determine what customer might
have sent us an incomplete or garbled fax message or credit card
transaction where all we know is that their address is "345 Main
Street"). But avoiding future expensive schema changes is the main one.
In addition, by normalizing, you are efficiently organizing data in a
database.
You also achieve two goals:
01. Eliminating redundant data (for example, storing the same data in
more than one table)
02. Ensuring data dependencies make sense (only storing related data
in a table)
Both of these are worthy goals as they reduce the amount of space a
database consumes and ensure
that data is logically stored.
If interested, to observe the dependency of your database, take a look
at the R:BASE Dependency
Viewer to illustrate it all for you!
R:BASE Dependency Viewer:
http://www.rbase.com/products/RDependencyViewer/
Have fun!
Very Best R:egards,
Razzak.
