>>There are times looked up data needs to be dynamic, but there are times it is necessary to know what the value was at the time of the data being entered and it cannot be changed by normalization rules. For example with a military requisition order that also shows the commanding officer. A report from normalized data would not reflect the commander that made the requisition, but rather the current commander since commander's change every couple of years. A current force status report would want a dynamic value. You would have to be able to show WHO the current commander of the unit is, as well as who was the commander at the time the requisition was made so the report would consist of BOTH normalized and denormalized data.
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>Tracy,
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>Your above example is NOT a violation of Normalization, the commander on the requisition and the current commander are two distinctly different data elements and the existance of both is NOT an example of redundant data.
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>Normalization always takes into account the domain definitions for data elements. For example keeping the tax rate on an invoice and in the tax rate table is NOT redundant because the domain definition for the invoice tax rate is "the tax rate at the time of this invoice", while the domain definition for the tax rate table is "the current tax rate". These two definitions are completely different and therefore they do not represent redundant data.
>
>This is a very common misinterpretation of normalization rules in that the complete domain definition for the data elements is not stated.

Jim,
Now we're starting to get somewhere. I understand the concept of breaking down the table(s) into related components. How far can/should I go in evaluation? Is there a way of determining whether a table has been normalized enough/too much? Should the tables be related? Can relationships be changed on the fly?

What about updating the tables with new data? I get 50K records a week. I'm looking at normalizing since traversing the table now takes so long. As a last query, is splitting a table the same as normalizing?

Sorry about the multiplicity of questions. It's these things that never get answered in articles.

TIA,
Pete