If you followed my last post, then you should now have a normalization configuration for the Computer table's CPU Type field. But as is, it doesn't actually do anything. Let's fix that!
But first you need to understand a few concepts (don't worry, they're not hard). Grab a cup of your favorite brain stimulant and read on:
Field normalization works with three different kinds of values, all of which appear (or could appear) in the normalized field. The three kinds are:
- Pending: These are the different values that actually appear in your system in the field being normalized, but which you have not yet decided whether they are Normal values or Alias values (see below). When you first create a configuration, these values are automatically collected (it can take up to a few minutes to do so). All values are Pending values until you decide to do something with them. As your system is being used, once the field normalization configuration is active, any values entered, imported, or discovered that are not equal to either a Normal value or an Alias value are automatically added as a Pending value. You can review this list of Pending values regularly to figure out what they should be, and fix them up if need be. This is the primary way you keep your data normalized as that pesky real world keeps dumping new kinds and variations of values into your normalized field. The picture at right shows what some of the pending values on my system looked like when I first created this configuration.
- Normal: These are the values that you've decided are the ones you want to appear in the normalized field. We're using the term "normal" much as it would be used by a database expert: when there are multiple ways to express a particular value, the Normal form is the one way you want it. For example, the pending values shown above are all different ways of expressing "Xeon" — and I want the Normal value for those to actually be Xeon. You can see in the example at right what Normal values I've decided I want in my instance for the CPU type. These values can be anything you want. In particular, they do not have to be a value that was a Pending value — you can create arbitrary Normal values.
- Alias: These are values that are another way of expressing a particular Normal value. For exampe, the pending values shown above all happen to be aliases for "Xeon". Probably the most important thing to remember about Alias values is that they're always associated with a Normal value, as you can see at right, where the four Alias values are associated with the Normal value "Xeon".
Ok, that's about enough for one day! Next we'll talk about Normalization Rules and how they and aliases work together to actually do the normalization...
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