RE: normalization
- From: david wendelken <davewendelken@xxxxxxxxxxxxx>
- To: Oracle-L Freelists <Oracle-L@xxxxxxxxxxxxx>
- Date: Tue, 1 Nov 2005 14:41:35 -0500 (EST)
It violates 3NF.
But the argument is moot. The correct question to ask is:
"Will the simplification and speed increases gained by storing the calculated
result more than offset the increases in complexity to keep the calculation and
the source fields synchronized plus the risk that you don't properly
synchronize them?"
FWIW, the referenced document uses the classically wrong example of:
> <http://www.alphabetcitydataworks.com/FundamentalsOfRelationalDatabaseDesign.doc>
data items = quantity sold and unit price
calculated value = line total price
The correct example is:
data items = quantity sold and line total price
calculated value = unit price
Try recording "3 for a dollar" using the first example...
Otherwise, the document looked quite good at a quick glance.
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