After you select a primary key from a list of candidate keys, you can designate some or all of the remaining candidate keys as alternate keys. Alternate keys are often used to identify the different indexes, which are used to quickly access the data. In a data model, an alternate key is designated by the symbol (AKn), where n is a number that is placed after the attributes that form the alternate key group. In the EMPLOYEE entity, “employee-name” and “employee-birth-date” are members of the alternate key group.
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