|Bookshelf Home | Contents | Index | PDF|
When you have determined which type of table to store the attribute in, you then have to decide what type of extension column to use. The extension column you use depends on the type of attribute. There are two types of attributes data—free-text and domained.
It is recommended that you use a Text extension column as a placeholder for free text attribute data. Text extension columns are available in fact, dimension, and class tables. The Text data type extension column offers the most character space; they are varchar (254).
It is recommended that you use Code Name and Code extension columns as a placeholder for domained attribute data. Referring back to the sample domained attribute State, the State column's domain of values is restricted to the states in the United States, which can be denoted by a code. For example, California can be denoted by CA. In this case, the code name is California and the code is CA. With domained attributes, you can issue codes to each possible value, because you know the possible values for this variable. However, do not use codes for columns that have too many values, because it could significantly slow the processing time. For example, even though you might use a Code and Code Name extension column for a state, you might not use it for cities.
If a code does not exist in the IA_CODES table and you want to use a lookup for the code name, then you must add the code to the IA_CODES table. Three possible scenarios occur when working with codes and code names. Each of the following scenarios are also described in Figure 42. The three scenarios are described in the sections that follow.
If the code and code name pair reside in the IA_CODES table and you load only the code column, the ADI resolves the code name through a lookup. (See Figure 41.) This is the way to enforce domained values. For information on adding new codes to the IA_CODES table, see Creating a Codes Mapping.
If the source supplies only the code without the code name, and the code and code name pair do not exist in the IA_CODES table, then the ADI tries to resolve the code name by a lookup. However, because the code and code name do not exist in the IA_CODES table, no data is retrieved. As a result, the ADI loads only the code into the IA table. This method does not enforce domained values.
If the source supplies the code name without the code, then the ADI loads only the code name into the IA table. (See Figure 42.) This method does not enforce domained values.
|Siebel Customer-Centric Enterprise Warehouse Installation and Configuration Guide|