Your database brings together information from different tables. For the database to work efficiently, each business object in your database needs to include an attribute that uniquely identifies each individual business object instance. This is often a unique identification number, such as a USER number or a serial number. In database terminology, this is called the primary key of the business object that corresponds to the primary key of the table. Keys associate data from multiple business objects and bring the data together.
If you already have a unique identifier for a business object, such as a set of product numbers you have developed to identify your configuration items, you can use that identifier as the business object’s target key attribute. You need to ensure that the values in this field are always unique: you cannot have duplicate values as a primary key. For example, do not use people’s names as a primary key, because names are not unique. When you map target key attributes, you must map them to a field that is unique to a single record.
When you set the target key attribute, the attribute icon changes from the attribute icon – – to the target key attribute icon – .